I'm still not as far in the system as most of you, so dont be alarmed if my efficiency in movement isn't at it's most economical.
For me, and this is purely based on sparring rather than street fights or anything like that, i usually use side stepping and cutting in using diagonal lines of movement, if that makes sense. I'll add a kick or so into this as I enter kicking range/distance, but I dont like to hang out in that distance for too long. Once I'm close to the being within arms distance, I tend to throw a lower faster kick mainly for the purpose of quickly cutting the distance and either attacking or using mun sao. Before I enter this distance, I may also use a type of shuffle where i twist my hip to switch my lead and rear legs. I mainly do this because, at least at my level and the level of the people I spar with, this sudden shift from either "southpaw" to "orthodox" or vice versa changes the situation enough that moving in shortly after leaves the opponent with less time to really think of what he's going to do. At this point, I feel that I'm completely engaged.
sounds like a long process but it really only takes a matter of seconds when applied.
Everybody wants to go to heaven but nobody wants to die...