Best way to start a instagram account

What is the best way to start a new instagram account?

I want this account to blew up like crazy... any tips which niche i should use? Also i have 4 accounts that are 2 months old where i haven't post anything... should i use one of them or should i make a new one?

You could use the old ones since aged accounts always work better and have less chances of getting banned, you can push the follow/unfollow limits further etc.
Let's see other people's advice about how to blow it up fast!