Good idea, I did the same thing

Things you can do to maximise your money while you're VIP:
- create some premium class chars i.e. warden/runekeeper
- fill up all your char slots as all chars created while VIP will have 5 bags and gold unlocked
- create your Legendary Item(s) and level it up as much as you can
- work on the deeds that you want if they are involve paid areas
Things to do just before your VIP runs out
- fill up your quest queue with quests from paid areas, they will still work after VIP expires
- fill up your auction house queue
- fill up your wardrobe
That's all I can think of right now. Have a look at this link which will be give you more ideas:
http://www.codemasters.com/lotro/freetoplay/faq/I have since resubbed again as they are very clever at getting your money!