I'm trying a Mamluks -> Arabia run. I've taken 90% of Mashirq, Arabia from the Red Sea to the Persian Gulf, and bits of Yemen; I've also vassalized Oman, so now my priorities are basically to diplo-annex Oman, possibly (diplo)-annex Yemen, and basically try to hit Admin 10 ASAP so I can get Arabia and all the fun stuff that comes with it like Empire rank.
Problem: Ottomans are after me. Bigger problem: They have guns and a 2-star commander. I have no guns, a 1-star commander, and to make matters worse Tunis abandoned their family and Egypt (will make them pay for their betrayal later.) They declared before my intended Polish alliance could be worked out.
Any suggestions of what to do? Appeasement could be a problematic strategy, because IIRC the province they're after is needed to form Arabia. Right now, I'm thinking I'll blow a ton of money and probably take a few loans on mercs, then sort out the economy later.
E: Alright, scratch that, I figured out what to do. I restarted after they crushed me. The trick, it turns out, is to deny them crucial territory early on, so what you should do is ally Karaman and feed them Ramazan and Dulkadir. This creates a buffer between the Ottomans and you, which buys you time to take more important anti-Ottoman measures, like allying one of their rivals. It also doesn't hurt to guarantee Byzantium--the longer you can stall the fall of Constantinople, the longer you can stall the Ottomans becoming an empire.