Quick and healthy kids dinner: two-tier steamer (electric/stove top). Water in bottom pan, piece of salmon or chicken wrapped in foil in next pan, veggies in top pan. All cooks together (although depending on veg you might want to cook meat for 5 mins first before adding veg pan).
Cut both ends off carrots and store in lidded Tupperware in fridge. They last weeks and never go bendy.
Tear dylon colour run sheets in half, they work just as well. Also, if using tabs where the recommended amount is two per wash, only use one. Same results, half the price.
For big tea drinkers: make a cuppa in a mug as usual, but also make one in a travel cup. Keeps it hot until you'd normally have your next cup, useful if painting or gardening (for me I do this when having a long bath, so i get to stay longer!).
Chuck peas/sweetcorn/broccoli into pasta water when making children's pasta and pesto.
Towelling robes for everyone means you only ever need to use hand or hair towels.
Campers: cheap shallow plastic basket/bucket from poundland or similar, lined with a nappy bag and a value nappy. Wee in the tent in the middle of the night without having to go to the loo (just place the container between your legs). The nappy absorbs to stop the wee sloshing about, and then you tie the nappy bag up. Just like a baby's nappy.
Milk can be frozen-always keep a one or two pint bottle in the freezer to save dashing to the shops.