Bank charges are generally penalties for unauthorised overdrafts, banks love them because they are huge in comparison to tiny amounts of lending. The key is discipline, ie if you know spending �10 will push you over your agreed limit and cost another �30 in fees, then, don't!
I know it's easier said than done but I have found in most cases a person can get out of the "need money/must endure charges" cycle in 1 month.
Does this sound familiar? overdraft limit is X wages go in each month and offset most of the overdraft possibly even put you back in credit. Trouble is at the end of each month there's not quite enough so for the last few days you are over your agreed limit, bang, charges for each indescretion making it harder and harder to ever get within agreed limits.
Solution. You have to live like you have no money for 1 month, you won't starve, you may have to go without beer and fags, you may have to stay in for a month. Once you've done it then it should be a lot easier to stay within limits and avoid charges.