I usually get right over the pile then throw the marker like 15-20 ft away. Sometimes I am going to cast and retrieve over the brush...sometimes I am going to throw on it with a slip bobber set just right...and sometimes I'm going to vertical fish over it. That depends on how deep it is mainly and how clear the water is. The deeper and murkier it is the more likely I will fish right over it. One thing about casting or slip bobber is I can throw beyond and work it back over it...catching fish around it too.
Be aware...sometimes to catch them you need to double anchor ....sit still...get quiet...and give the fish some time.You ever squirrel hunt and when you walk in crunching those leaves you see nothing...but after 15 minutes or so the activity picks back up? Fishing is like that sometimes. You banging around and the trolling motor is whirring or you blew up within 30 yards of your target with the outboard...you need to let things settle down sometimes.
I rarely use my markers any more...but they do come in handy at times and they are a good learning tool. Biggest problem is they tip people off to a spot even more so than just being there with the boat. I hardly see anyone use them anymore...a guy complained to me the other day about people seeing him catch fish on a spot then they mark it on their GPS.
I usually start looking at the brush that is at the location and depth I figure the fish are going to be. Like sometimes I figure they will be in the main body of the lake on humps or ledges...or main points or secondary points...or sometimes further back in a cove or creek arm..so I break it down like that. Always looking to develop a pattern for the day...and watching for it to change. Somedays it won't...others they may be one place in the morning and another later in the day.
I rarely fish a spot I am not marking fish on to my liking. I have occasionally caught them when they were buried in the brush enough it is hard to separate them. But with DSI now it's easier.