I save mine for 12-18months and then treat the family. I have recently boosted mine to pay a large amount off a holiday booking to Butlins. . result £210 off the balance :). Also use them for Alton Towers & Blackpool Pleasure Beach.
I normally use them for Tesco boosts tend to use restaurants as you get 4 x the value [this is not strictly correct as by not using your Tesco points you can get offers / vouchers that do not apply when you pay with vouchers.
Also use them for train travel via Redspottedhanky and I somrtimes use them where there is a 'Double Up' in store at Tesco, it always amazes me how many people use them at face value in Tesco
I love them! Last year I saved them up all year and then boosted with Golsmiths - I now have a sparkly diamond ring for free!!! - thanks Tesco
I save my Clubcard points throughout the year using the Christmas Saver scheme; last December my Mum's shopping bill was halved!