Woolworths and Boots do the 3 for 2 offers and you can pick up some cool little bits and bobs there. Some of the mini catalogues/gift guides like Argos and Boots have sections in there for stocking fillers and gifts priced up to �5.
Try little reto shops if you have one near u there is one in Plymouth and Exeter called Pumpkin for example.
www.prezzybox.com is quite good and when you register you get a �5 of voucher when you spend �20 which is quite useful if you have a few things to get!
Also as its my birthday today they sent me a �5 voucher with no conditions such as minimum spend!!!
i had to do it last year, try BHS has excallent gift for really reasonable prices theres funny ones as well as "nice" ones! if u dont find anywhere there try matalan?