I think you use momentum strategy to get income, no big deal but I'm afraid every momentum has different impact ( not always same ). Use momentum strategy need big money and fundamental analysis to get good analysis. I'll not teach you about it but how about you try it by your self and see what happen. Not always work but you can learn something.
It not always possible to short and get a profit so there needs to be a wait and watch strategy for traders as well. I know it does not sound like a strategy but if you apply it during the bear market you can do recon without having to lose money. Shorting should be done by those who are experts in the technical analysis and not something that I would suggest a newbie to know except for academic purposes.
Indeed if you are borrowing money to short coins you are posing a risk of getting bankrupt as well.