I'm in, for Q1 at least so I can replenish my savings after Christmas! My problem is spending way too much money on food/drink - there are only 2 of us but including a takeaway we spend at least £150 most weeks, and I read that the average for 2 people is about half that. We basically need to eat cheaper food, and not spend so much on snacks, treats and alcohol.
I also bulk buy if something is on offer, which in theory is sensible, but in practice means usually I'm inflating the amount of my weekly shop, and for some reason the benefit of that doesn't seem to come through in future shops - I just buy more of other things.
Weirdly I will then deny myself new knickers, shoes or something I want for the house because 'I can't afford it', although I've probably spent at least £600 on food that month!
So plan for me is significantly reduce food bill, put most of the money in savings / pay off my interest free credit card balance, and then use a little bit of the savings to 'thoughtfully purchase' myself something new as a reward - this month it's going to be a new dressing gown for £25. So far since 1 Jan I've spent about £100 at Tesco, and DH has done a couple of small top ups so we are doing well.
I've also unsubscribed from about 50 marketing lists since 1 Jan, and have more to do - I'm a sucker for '20% extra off sale!' and similar.