How I decide what products to buy

I use various methods when I decide I need something new.

1) Make Up Alley Best Site Ever IMHO. I use Make Up Alley Advanced Search and plug in the following;

• Min reviews 20 - because a few people's overly enthusiastic view based on hype is worth little, but at least 20 saying the same thing means this may well be winner.
• Lippies 3.5 + - I would say 4 but a few if my HG (Holy Grail) products are only rated 3.6 or so, as it depends on skin type/ age/ colouring.
• Packaging does not concern me, worse case I can decant them into something more desirable. The only things I flout this rule for are powder compacts and lipsticks as you use them in public

2) Paula Begoun's Beautypedia Don't always listen but is generally pretty sound on skincare.
3) Amazon Reviews
4) Google Shopping for pricing
5) Other Beauty Bloggers pictures/videos

How do you decide what to buy, any tricks I'm missing here?