There are more options possible but one of the best you can have these days is doing trading because campaigns is not so profitable anymore like back in the days of course it can help you a bit if you are also doing them.
Signature campaigns are still profitable, only that it is just being abused by many. I do believe that in signature campaign isn't the way to earn more bitcoin, and trading too, if you only have few satoshis in your exchange wallet, that won't work, you won't achieve that even in two months. 1 bitcoin needs bigger capital too, that means you won't just enter big capital, you need to put in effort too and most of all, skill, the more skill you have, the more chance that you'll earn 1 bitcoin in a month.