if your lucky enough, get a clone of a mutant that has whorled phyllotaxy. instead of growing bilaterally, they grow trilaterally or even quadlaterally. some south american sativas are more known to mutate like this. normally mutant plants are bad because they lack the good traits of a normal healthy plant, but you can get lucky and not have those bad traits.
im not sure what your lighting setup is, but if your looking for your plants to stretch less(have less space between nodes), use a MH instead of a HPS during veg.
you may already know about this but another factor is choosing your cannabis strain. there are 3 species: indica, sativa, and ruderalis. indicas normally grow short and bushy, more side branching. they also make you more tired because normally have more CBD to THC ratio. sativas grow taller with less side branching. they also make you less tired because they normally have less CBD to THC ratio. of coarse you can greatly manipulate this by the techniques you mentioned; fimming, lst, etc. finally the ruderalis species are basically garbage themselves as far as potency. they have the trait of auto flowering. they flower over a certain amount of time has lapsed as opposed to the normal 12/12 light cycle switch. ruderalis has been crossed with indicas/sativas to make up for the high potency. they are low yield and you cannot clone or rejuv them however. they die after harvest. they also stay very short and bushy.
so if you get an indica, you shouldnt have to top as much. almost all strains besides autos are a cross of indica/sativa species. find out what indica/sativa suits your needs best. there are a few that some claim to be pure though. they are known as heirloom. an example is the heirloom sativa known dr. grinspoon.
