Throwing my 2 cents in on "slippery".
Being as aerodynamic as possible in all situations is nothing but a positive. Even in the pack, you're seldom 100% protected, and at some point you'll have to take some wind either at the front if you're chasing, or while you're moving up outside. Race efforts, be it a crit, track or road race, are
cumulative. Reduce your output at any point in time during the race and you're that much fresher at the end. Being a little slicker and a little fresher...take a look at the last pic and you can see what a little difference makes.
I've spent a long time getting more flexible, and gradually lowering my position to where it is today. Lower is almost always better. Looking at the 2nd and 3rd pictures, off the bike the guy leading in the 2nd picture is my height, the guy leading in the 3rd picture is 3 inches shorter and the guy behind me is just a slight bit taller. But you wouldn't think so looking at those examples. And the guy behind me is getting less draft, which is one thing that I haven't read anyone mention when a discussion of wheels or other aerodynamic advantage is brought up.
You make your competitors work harder
even if they are on your wheel. Worth noting that if I'm in a break with a teammate I'll ride on the hoods to give them a little more draft. If I'm in the drops I don't give much of a draft, and if I drop into the IAB (Invisible aero bars), my position is better than a lot of folks on their TT bikes. Being slick has kept me in races even when my fitness hasn't been very good.
So job one is to work on getting longer and lower. I do a lot of stretching to help this, and
specifically train in the drops for extended periods. I even climb in the drops so I develop the ability to push power while in that lower position, and I climb in the drops out of the saddle (I picked this up from watching Marco Pantani) so I'm that much lower if I'm attacking or soloing into a headwind on a climb. That same training effort transfers well to sprinting BTW.
My bike is set up to facilitate this. Which is job 2. Tidy the bike up as much as possible. Big loops of cable everywhere just catch wind. An aero chainring will help a little. My stem is slammed and long, and I use a traditional bend with a deep drop. And whenever possible I run the deepest rims I can, wind and course specific. My number is pinned in 6 spots and positioned so that my shoulder blocks the leading edge. Tight skinsuit. Every little bit helps.
Job three might be the IAB. Again, I specifically train in this position a bunch. It's something that every rider who uses it should test though, some people are more efficient in the drops.
Last piece of this is head position. I do so much time trialing that it seems I "turtle" and keep my head down regardless. There's a lot of wattage there. Keep that in mind.
Enough mention has been made about pack positioning but I'll add that you should always know where the wind is coming from and be thinking ahead to where the course changes direction. Develop the skills and knowledge so you can get people to ride like they know what they are doing. Learn how to rotate a paceline. Learn how to echelon and practice this.
At a recent stage race 5 of us got OTF in a brutal crosswind. I was the only guy who was aware enough to get us quickly into an echelon, rather than just guttering everyone in our potential breakaway. We eventually got shutdown but the other guys had to work their tails off to catch us.
Bottom line is that it's practice, adaptation, and knowledge. Az, for a bigger guy, the impact can be substantial.