My Grandma has always given us fab pressies at Christmas. Never expensive or showy but always lovely.....
She's usually 'packaged' presents as a little 'treats hamper' filled with things:
e.g. From being small we cooked together and some pressies have been unusual food treats (a star fruit one year, special ice cream to try, chilly sauce, nice chocolates...)
Plants - I still have a cactus that she gave me when I was 7, last year she potted bulbs up for our new yard.
My sister is into fashion, clothes etc so my Grandma used to take her into town (quite far from where we lived and we were not allowed on our own). They would have a budget but my grandma would take her into any shop she wanted (not possible when shopping with busy parents!) and they would try on loads of stuff and have fun.
Often she gives us a little treat money and although many feel this is unpersonal she always asks us to tell her what we've spent the money on. When we got married she gave us money and we got our pans with it - they are special to us because they were with her money.
Tescos vouchers could be good....could buy CDs, games, clothes, foody treats, toys....
Don't know if this is useful!