If the fish are under pressure and know what anglers rigs are then try and camoflague your end tackle to the best of your ability. Perhaps use a brown coloured hooklink like the ESP Stripteaze, Korda Hybrid, Sufix Superskin or Camo Skin etc, etc, etc. (The list goes on TBH). You could even make a combi link from flourocarbon and braid.
But it all depends on what you have confidence in.
To find the clean gravel areas use your marker rod or just have a lead about and look for the tell tale tap, tap, tap, tapping on your rod tip.
PS, im fishing a lake with the same bottom make up as you at the moment and today before i left i actually got a sample of sand from the margins of my swim and im actually gonna coat the leads with it once its dried out. It may not make a difference but any edge i can do to help me catch will increase my confidence.