BUY EXPERT CREW FOR YOUR PREMIUMS!
I know this might be really obvious, but I went YEARS without buying expert crew for my A-5C. I always hated this plane. I felt like it never did what I wanted it to do. Sure, it isn't actually that good, but I recently bought expert crew for it, and it's a night and day difference. I feel like I can actually control the plane now (I had my crew skills maxed out already). I've been holding myself back for so long, since I was too cheap to spend the 920,000 silver lions on expert crew. I've easily made that back, and then some. I'm finally making progress in the Chinese air tree again, after months of stagnation. Every time I used the A-5C was just pure misery. Now, I feel like I'm actually flying the plane.
Don't be a cheapskate like me. I don't care if it costs over 1 million SL. BUY EXPERT CREW IF YOU PLAN ON GRINDING WITH YOUR PREMIUMS FOR ANY SIGNIFICANT LENGTH OF TIME.