What we found useful was realising how much we had to raise EVERY MONTH, and that if we didn't raise £270 THIS month, then what we didn't raise would be bigger in future months.
As a generalised rule of thumb, we did better organising events with just one other family (or even just our own family) as you then get all the money / half the money rather than sharing what probably won't be a whole lot more income, between a greater number of people.
For example, if you can muster enough of your own family to run a quiz night and run the bar, then do it in 1s or 2s rather than between 6 families.
Don't underestimate the regular drip feed of small amounts too. Some examples from my dc's units:
One family made cakes to order for the local retirement home (where residents had kitchens without ovens) - I think they had an "in" as Grandfather lived there
One lad used to make Choclate concrete and sell it at his Rugby club each week
One had some football club cards and 'ran a card' after the match in the bar at his local non-league football club each week (the cards have names of 40 teams on. You sell each for £1 or £2 and draw it (is usually a scratchcard thing if you buy them commercially or you can make it with the team sealed and stuck to the card or you can draw it like a raffle). There is a £20 prize and you keep £20 for 30mins work...... obvs can transfer to anywhere where there is a crowd in a bar on a weekly basis, doesn't have to be football
One sold things on e-bay......donated from friends and family, but also put a note through the door of all houses on the road and got lots of donations. Obvs someone has to sort the postage / delivery, but someone at our Church does it as an ongoing thing and makes about £2k - £4k a year
If your young person can cope with early starts, then a car boot sale can be stocked in a similar way
Arrange events that people actually want to go to, and then you spread the cost / aren't constantly asking grandparents or their Scout Leader to be digging deep. (It's why cake sales are popular)
Ask at school if you can do a cake sale / coffee or tea provision at parents evenings
Tuck shop at your Scout Group each week - works better if you have Scouts arriving as the Beavers go home.....your YP is there anyway and is a steady income stream
Tuck shop at District events
Do the coffees and have a cake sale at the Group and District AGMs - lots of generous people who understand what you are doing.
When you do a cake sale, (unless to small children) don't 'price things', ask people to donate what they would like to....... particularly where the 'crowd' is older people (say after a Church Parade) you will make a lot more. We often have people giving us a fiver and taking one small cake.