Infiltration tactics
Though not yet effective, their promise of breakthroughs in the future was held out.
The British Third Army employed tactics giving platoons more independence at the Battle of Arras in April 1917 (most notably the capture of Vimy Ridge by the Canadian Corps), following the reorganisation of British infantry platoons according to the new Manual SS 143. This still advocated wave attacks, taking strongpoints and consolidating before advancing, part of "bite-and-hold" tactics, but this did allow for more local flexibility, and set groundwork for low-level unit initiative, an important aspect of infiltration tactics.

Hurricane bombardment: A new method of artillery use evolved during World War I, colloquially called hurricane bombardment. This is a very quick but intense artillery bombardment, in contrast to the prevailing artillery tactic of long bombardments. Various forms of quick bombardments were employed at several times and places during the war, but the most successful use of hurricane bombardment was when it was combined with German infiltration tactics in which local forces take immediate advantage of any enemy weak points they find.
After the start of trench warfare in World War I, and artillery moved from direct fire to indirect fire, the standard use of artillery preceding any friendly infantry attack became a very long artillery bombardment, often lasting several days, to destroy the opponent's defences and kill the defenders. But trenches were very soon extended to avoid this; they were dug deeper and connected by deep or even underground passages to bunkers far behind the lines, where defenders could safely wait out bombardments. When the bombardment stopped, this signalled the start of the attack to the defenders, and they quickly moved back to their forward positions.: 13–14  This practice of very long bombardments expanded over the course of the war, in the hopes of at least causing a few casualties, damaging surface defences like barbed wire lines and machine gun nests, and exhausting and demoralizing the defenders by the stress of being forced underground for so long, the noise and the vibrations.
The Allies, led by the British, developed alternative artillery tactics using shorter bombardments; these sought to achieve success by surprise. (This was also to use limited ammunition supplies more efficiently.) The effectiveness of short bombardments was dependent on local conditions: the targets had to be identified and located beforehand, many artillery pieces were needed, each with ample ammunition, and the preparations had to be kept hidden from the defenders.
To further increase the chance of success, these short bombardments were sometimes followed by barrages. Many variations were devised, including moving barrages, block barrages, creeping barrages, standing and box barrages. The goal of an artillery barrage was to target a line of impact points repeatedly so as to impede infantry movement; these lines could be held in position or slowly moved to inhibit movement by the opponent or even force them into poor positions. The barrage plans were often quite complicated and could be very effective.

The Germans also experimented with short bombardments and barrages. German Colonel Georg Bruchmüller tailored these significantly to integrate well with infiltration tactics. He began to perfect this while serving as a senior artillery officer on the Eastern Front in 1916. Hurricane bombardments avoided giving the defender several days' warning of an impending attack – vital for infiltration tactics. Barrages had to be carefully limited for use with infiltration tactics, as both the barrage movement and infantry advance must keep to a timetable, necessarily very methodical and slow to avoid casualties from friendly artillery; this takes away almost all initiative from the advancing infantry. Barrages with infiltration tactics had to be more intense and precise, and quickly moved to deeper targets. Bruchmüller enforced having artillery aim from the map, avoiding the typical practise of firing several registering shells before a bombardment to adjust the aim of each gun by trial-and-error, alerting the defenders before the full bombardment. Precise aiming without registering shells requires expertise in ballistics with angles and elevation calculated from accurate maps expressly designed for artillery use, knowledge of the effects of altitude and local weather conditions, and also reliable and consistent manufacturing of guns and ammunition to eliminate uncontrolled variation.: 12–13 
Bruchmüller devised intricate, centrally-controlled firing plans for intense bombardments with minimal delays. These plans typically had several bombardment phases. The first phase might be bombardment against enemy communications, telegraph lines, and headquarters, roads and bridges, to isolate and confuse the defenders and delay their reinforcements. The second phase might be against the defenders' artillery batteries and the third against their front-line trenches to drive them back just before the infantry assault on those positions. The last phase was typically a creeping barrage that moved forward of the advancing infantry to quickly bombard positions just before they are attacked. The phases were usually much more complicated, quickly switching between targets to catch defenders off guard; each bombardment plan was carefully tailored to local conditions. The type of shells depended on the target, such as shrapnel, high explosive, smoke, illumination, short-term or lingering gas shells. The total bombardment time was usually from a couple hours down to just minutes.: 74–76 
The creeping barrage phase is often held out as a key part of infiltration tactics, but its use in infiltration attacks is limited by the fact that the rate of infantry advance cannot be predicted. The quickness, intensity, accuracy, and careful selection of targets for maximum effect is more important.
Allied and German styles of bombardments could use tricks of irregular pauses and switching suddenly between targets for short periods of time to avoid being predictable to the defenders.
Bruchmüller's hurricane bombardment tactics in close cooperation with infiltration tactics matured by the time of the German victory at Riga on 3 September 1917, where he served under General Hutier. These bombardment tactics were disseminated throughout the German Army. Hutier and Bruchmüller were transferred together to the Western Front to take part in the Spring Offensive of 1918, where Bruchmüller's artillery tactics had great effect on quickly breaking the British lines for Hutier's 18th Army. Following that initial attack, the artillery had less effect, as infantry forces advanced faster than artillery and munitions could keep up.
After World War I, use of radios to quickly redirect artillery fire as needed removed any exclusive reliance on time-table driven artillery bombardment.

Dien Bien Phu: At the Battle of Dien Bien Phu (1954), Major Marcel Bigeard, commander of the French 6th Colonial Parachute Battalion (6th BPC), used infiltration tactics to defend the besieged garrison against Viet Minh trench warfare tactics. Bigeard's parachute assault companies were supported by concentrated artillery and air support and received help from tanks, allowing two companies (the 1st under Lieutenant René Le Page and the 2nd under Lieutenant Hervé Trapp) numbering no more than 180 men to recapture the important hilltop position of Eliane 1 from a full Viet Minh battalion, on the early morning of 10 April 1954. Other parachute battalion and company commanders also used similar tactics during the battle.

See also: Military deception
List of military tactics
Raid (military)
Extraction (military)
Frogman

Notes: 

References: Davidson, Phillip B. Vietnam at War: The History, 1946–1975. New York: Oxford University Press, 1991. ISBN 0-19-506792-4, ISBN 0-89141-306-5.
Gudmundsson, Bruce I. Stormtroop Tactics: Innovation in the German Army, 1914–1918. New York: Praeger, 1989. ISBN 0-275-93328-8.
Simon Jones, Infiltration by Close Order: André Laffargue and the Attack of 9 May 1915.
Kraus, Jonathan. Early Trench Tactics in the French Army: The Second Battle of Artois May–June 1915. Farnham: Ashgate, 2013. ISBN 978-1-4094-5500-4.
Kraus, Jonathan. Podcast: The Second Battle of Artois, May 1915: the new turning-point.
Laffargue, André. The Attack in Trench Warfare Impressions and Reflections of a Company Commander by Capt. André Laffargue 153rd Infantry, French Army, Translated for the Infantry Journal by an Officer of Infantry. Washington, D.C.: The United States Infantry Association, 1916.
Samuels, Martin. Doctrine and Dogma: German and British Infantry Tactics in the First World War. New York: Greenwood Press, 1992. ISBN 0-313-27959-4.
Samuels, Martin. Command or Control?: Command, Training, and Tactics in the British and German Armies, 1888–1918. London; Portland, Oregon: Frank Cass, 1995. ISBN 0-7146-4570-2, ISBN 0-7146-4214-2.

Further reading: David Goldovt-Ryzhenkov (Translator from German) 2018: Examples of Reconnaissance and Security Operations in Defense, 1942/1944. German Manuals
House, Jonathan M. Toward Combined Arms Warfare: A Survey of 20th-Century Tactics, Doctrine, and Organization. U.S. Army Command General Staff College, 1984.