Looking for simple guide on follow/unfollow methods

Can someone outline a simple follow/unfollow method either paid or free that is easy to follow?

right now I am just going to like accounts and hashtags and following users. Currently I am using crowdfireapp to unfollow but the free account is limited to 25 unfollows and I really don't have a process to weed out the users I have previously follow/unfollowed. I was wondering if someone had a simple guide, software or app suggestion on getting this going. Does someone also have the current safe limits for amounts of follows, unfollows and max follows allowed?

Sorry if this information has already been posted I am just having a hard time rounding up all the specifics in one place.

there are some bots which are all discussed here. you should read a little and not only ask for basics.
bots are not free.

but id you look there are some macros which are shared for free. they can do the basic stuff as well in case you don't like to invest any money.

Can you suggest a good bot for one account that keeps track of previously followed?

The main ones are Massplanner, Followliker and maybe Instagress. I use Massplanner and it works well. Though before Massplanner, there is a member here mike915 who gave me a script for follow/unfollow for free. It works with Iconosquare and does the job sometimes. You can PM him.

i use Follow liker which is ok.

Thanks I gave unfollowspy a shot but it was showing some people I explicitly followed and they followed me in my not following list. So I can't really rely on it to be accurate without whitelisting and testing it further.