What situations?

['ol pajamas]

How true, presentation is #1. Start with a fly you have confidence in, regardless of what is in the water. However, swim it where the stripers are. If nothing is happening and you know there are fish, then the work begins. I prefer using 2 or 3 flies on dropper to find out what's happening. Swim them on the surface and then get them deep.
Certainly the more one fishes the more one encounters exceptions but we have to start the night with something on. In all those situations that you mention what is most important is to let the most fish see your offering for longest period of time possible.

[pmueller]

Some great advice in that last few responses. Keep it simple first,get confidence in your flies and techniques. Deceivers poppers clousers then work up from there.
Work hard at getting the fly in front of the fish. You may have to work a particular piece of structure for a while to get a hit.
Keep working and practice casting. Mending is a great tool, dead drifting is a killer.