Continuity editing is the process, in film and video creation, of combining more-or-less related shots, or different components cut from a single shot, into a sequence to direct the viewer's attention to a pre-existing consistency of story across both time and physical location.
The simplest way to maintain temporal continuity is to shoot and use all action involved in the story's supposed duration whether it is pertinent or not.
Continuous diegetic sound helps to smooth temporally questionable cuts by overlapping the shots.
Match on action technique can preserve temporal continuity where there is a uniform, unrepeated physical motion or change within a passage.
A dissolve is a simultaneous overlapping transition from one shot to another that does not involve an instantaneous cut or change in brightness.
Both forms of transition (fade and dissolve) create an ambiguous measure of ellipsis that may constitute diagetic (narrative) days, months, years or even centuries.
It cannot be argued that one constitutes short ellipsis and the other long however, as this negates the very functional ambiguity created by such transitions.
A flashback makes its time-frame evident through the scene's action or the use of common archetypes such as sepia toning, the use of home-movie style footage, period costume or even through obvious devices such as clocks and calendars or direct character linkage.
Montage is achieved with a collection of symbolically related images, cut together in a way that suggests psychological relationships rather than a temporal continuum.
However, if wishing to convey a disjointed space, or spatial discontinuity, aside from purposefully contradicting the continuity tools, one can take advantage of crosscutting and the jump cut.