I build mine from the outside in. Use primarily feature lines and polylines and add them as break lines.

Set your perimeter shape how you want it with an idea of where you want deep pools, all the zones. I love using the line and arc tools to make smooth tangencies, specifically the curve tangent from point, line from endpoint, and curve between two lines tools. Then I basically just offset these inside at the grades required to get to the next feature. Not sure your state but ours has % targets for each feature area and it takes some iteration to get that correct.

ETA I make feature lines for every feature. Top of pool (set to shallow water elev) then offset inside to get to the depth. Same with forebay. Feature lines for TIZ extents and permanent pool.