Dirt Diva nails it with her answer. But I would just add: it's not just a question of how you want your legs to look, but how you want them to feel and function?
What I mean is, I train my legs differently at different times depending upon my larger fitness goal. When I am doing a lot of running, or trying to lean out the legs a little, I engage in a lot of leg-heavy cardio days rather than over loading with the heavy weights on leg weight training days. In this respect I am trying to build a more endurance leg week and an endurance leg feel. I don't want to hit the ground running with legs that feel like lead because of very heavy weight training or an exhaustive weights for legs session the day before. The heavy leg feeling is anathema to me when running. I want my legs to feel worked, but not depleted, I want them to feel more elastic than heavy, if you catch my drift.
So, I might do a selection of the following type workouts across a week, 10 day, 2 week period, all depending:
--LowMax (blasts that target the legs, no weights, endurance training),
--Xtrain Cardio leg blast or whatever it's called! ( plyo, HiiT blasts for legs mixed with medium weights to fatigue the muscles, again aiming for endurance effect because the work on the legs never lets up during this workout)
--two short CTX step cardios back to back (my faves are CTX All Step and CTX Step & Intervals, both end with interval work, leg intensive)
--Imax 2 (leg intensive blasts)
--One leg training day like GS Legs, PLB
--Runs at the gym on the treadmill which I follow with 1 hour of leg weight training with machines (leg press, hamstring machine, glute blaster, adductor and abductor machines), interspersed with core work after each leg exercise and a load of non-weighted walking lunges, between 20-300, all of which supports stability and strength for running
--12 mile power walks outside when weather good
When I do this kind of work, I am going for the functionality of the leg muscles to improve and assist my running. How my legs will look is the result of that functionality. But the end effect, for me, is lean and strong. The overall aim is endurance.
I don't tend to do a lot of total body weight workouts. My upper body is ectomorph and I'm a hard gainer in the upper body. I need to lift heavy for the upper body and I find the weights on total body workouts are not really what I need. I tend to train the upper and lower body separately, as Dirt Diva does.
Clare