I'm a newbie to.
Another cheap thing for the hols is to invite your DC's friend for the day or a sleepover. They'll be happy with a sandwich and a basic tea if there's the offer of some biscuits (or chocolate) and crisps (can both be value or shop brand!). Sports, games, art things, old DVD, or a local walk or trip to the park can all be done fairly cheap. If you have older ones, give me a couple of pounds and they'll be happy to potter off and spend it in your local supermarket/corner shop.
I'll be spending loads in Lidl this week, went yesterday and today spending £19 so far. I do my food shopping on foot, so trying to top up on loads of cans, cereals to save dragging DD there too much in the holidays, as it's further away than Tescos.
Luckily for me I think I only have to buy blouses, skirts, trousers, tights and school shoes this year - problem is it'll be the whole lot next year including a £58 blazer!