Gift ideas needed for three children I don't really know very well

[BurningBright]

12 year old boy
9 year old girl
8 year old boy

They are siblings, budget is about £10 to £12 each.

I could probably think of something for the girl, but I'm totally rubbish at presents for boys and 12 year olds are an anathema to me, so double whammy there.

Any idea? Please?

T shirts!

Thanks, Creampie