Roll casts with large loops will keep your rig from changing direction (which causes tangles) .. strip line and raise your rod tip until your rig is near the surface, wait half a second for the line to relax and continue with a regular cast, practice this and incorporate a little haul on the forward cast and you will eliminate 90% of your tangles..
I fish an indie, swivel, worm, and two nymphs pretty much exclusively and tangle very little .. one thing to watch for is that your rig does not land across your fly line, if this does happen recast or mend quickly or as your rig sinks it will tangle across your upper hardware .. weather it be your indie, worm or whatever ..