I was looking for some ways to increase my profits and eventually decided on margin trading. I am aware of the risks, but the potential gain impresses. What should I consider before going in for margin trading and which exchange offers more favorable conditions for that?
Please don't even think about margin trading before you have your feet wet with normal spot trading and some experience with the testnet aka a demo account. Most of people lose their accounts and believe me you don't want your tuition to be that expensive.
So trade on the testnet as long as you need to become comfortable with order placing, risk management, taking profits and then start with a small account.
As for platforms I recommend Deribit and Bybit. Bitmex is famous for those server overload issues so I'd stay away from it.