I'm fairly new to saltwater and flats fishing so this might be helpful just in that I have recently been where you are. I wrote this in another forum but it might be helpful to you:
Regarding casting distance and casting practice I'd like to add something that I wish I knew when I just started out.
If you will be doing any sight casting, which has been talked about here, I think it would be helpful for you to practice casting starting with the fly in your hand. I spent my first year working on distance. My second year I worked on accuracy. Now, in about my third year, I am trying to also practice my distance and accuracy from the ready position.
I have been in many situations wading or on the bow where I think, "wtf, I KNOW I can make that cast!" What happened? I figured out that if I practice casting to a bucket at 50ft and I make the same cast for 30 minutes, I am only practicing for one scenario. When it was time to make a 50 ft cast starting from 0 ft, all of a sudden it was harder to get the line out, judge distance, cast well, have the appropriate casting stroke to match line out, etc.
So now, in general I practice that 50 ft cast, but I also practice casting starting with the fly in hand, quick casts, 20 ft casts through 90 ft casts, various flies, all wind speeds, all wind directions, back casts, off shoulder, side arm, distance without looking back, distance with looking back, no haul short shots, no haul long shots, crouching, kneeling, sitting, handstands, cartwheels, etc. I also try and practice some of the 5 fundamentals of casting in each session. If it's not a specific drill then I try to at least be aware of what they are while casting.
In addition to the above, I would suggest you get a tripod so you can video yourself. I can find the problems in my cast but I have an expert to help me with solutions for the problems. Get some in person lessons and take the time to find a good one that you really like.
I can tell you I've seen a surprising number of stripers, a few bonefish and permit (important to note that I am battling 0 against these monsters) at less than 40 ft. How do you hit a fish at 9 o'clock 25' with your fly in hand? It's not the most comfortable shot but if you've practiced it a dozen time it might work when it's game time. I practice a bunch of these little flips and a bunch of long ones too. So my bread and butter is 40 - 60' but I've practiced plenty from 20 - 40' and 60 - 80'.