I had about £4.5k on credit cards, now will be debt free by April having worked away at it for three years - paying off at £150 per month plus a few 'one off payments' from ebay sales or work bonus (not large but avoiding the temptation to 'spoil myself!')
I moved the debt around always onto a 0% card (see moneysaving expert how to reduce debt in a common sense way) but don't use any credit cards to add extra - or if you do spend on one then have that one set up to pay off in full automatically via direct debit each month so there's not a temptation to leave it - as it then starts another vicious circle on another card.
Then live on what you earn and build in a set amount as a direct debit to gradually reduce the debt (say £100 a month or whatever you can realistically afford to pay off each month).
The key bit is don't buy what you can't afford (clothes/magazines etc) and ask if you really need anything before you buy it. Don't put anything on credit again - for me that meant no holidays for a while and buying less clothes. There is also a big saving in making packed lunches, avoiding starbucks, buying magazines - little things that you don't really notice but really add up.
Make a strict budget and a plan to get rid of the debt - there is no other way and you will feel a million times better when you are on top of it. No more guilty purchases - I know cos I've been there. Also, in that time, I have also managed to get married and have a baby whilst reducing debt and we've just had an offer accepted on a house so the main thing is to have a budget and stick to it.
In terms of other things - yes, Quidco is great, or search for online coupons for money off. However, the main thing is whether you actually need to buy anything. Also, check you are getting best rates for insurance, electric, check you mobile phone is the best deal, or if you have satellite TV, broadband - see if you can reduce costs of those or get rid.