Following Tweeps back
There are a lots of people who will follow you, but that doesn't mean you have to follow them all back. Some people do, but It really depends how much time you have to spend on keeping your account tidy. If you tidy up on a regular basis its probably worth taking the time to read each individual bio. You won't do this if your number grow very rapidly.
I once merrily clicked on a whole group of people I didn't know - not realising that I was then following a group of women who were part of the sex trade. I then had to spend some time banning them all so they could have no contact with me. However this was not before some very unsuitable tweets had appeared in my Twitter stream.
1. Return to the main menu and select 'Manage Twitter' and from the drop down menu 'Reciprocate'
2. You can now follow exactly the same process that you did before to flush people out and you can tick those you want to follow. and the click on 'Follow'. Before you move onto the next page - make sure that it says 'Last Action' followed by each person you selected.
One service I have used and is quite good as well is who.unfollowed.me. It is essentially a very similar service that allows you to keep track of who has unfollowed you.