The league I have been playing for several years was always 10/12 total teams. This year it's bumped up to 14. Besides needing more players deeper into a draft to fill your teams. Is there anything else that you should focus on??
I have played a few. It is definitely tougher but the strategy probably isn't different from what you are already doing. Never have 2 kickers. Load up on backup RBS in case of injury. If the benches aren't short it will definitely be slim pickings on the wire every week. I think you need to pay more attention to the bye weeks when drafting than in a smaller league.
Check the waiver wire settings. If you HOLD your spot week-to-week until you use one, make sure you hang onto it.
Risk aversion is always your goal. In a 14 team league you need to have exposure to upside in order to win. You need to balance stability with high-upside. Depth is critical, but you don't want to build a depth chart that is all floor and no ceiling and vice-versa.