Usually it doesn't matter whether you are working it straight up or at an angle. But here are some other considerations:
(1) Depth of fish: You can spook fish if depth is less than 15 ft and you are right over them with boat. The clearer the water the more likely to happen. So once I locate fish in these depths, I'll park off a ways and cast to them.
(2) Area of coverage: Once I mark fish with toss over marker I'll search around to see how far and in which directions the fish extend down on the bottom. I'll note where all they are in relation to the marker I threw out. Then I'll park boat where I can reach the most fish. I may be over some and in casting distance to the others. This way I can catch the most fish from a particular structure. If the fish stop biting, it usually means they moved, so I'll search around again, find and mark them and set up as previously. If wind is anything more than light, I'll park upwind so we can cast down wind to avoid backlashes.
(3) If you have novices on the boat, the easiest way to catch fish on structure is to find them on a 20 ft or deeper hump and park right over them. The novice doesn't have to cast - just let down lure to bottom and work vertically. I use a Mepps spinner instead of slabs and this works great. I just tell novice to let #4 Mepps to the bottom, take up the slack and reel it up medium to fast speed. Fish hit it coming up and hook themselves.