You can disassosciate your interests from google by going here : https://www.google.com/ads/preferences and make it permanent by using IBA opt-out plugin : https://chrome.google.com/webstore/detail/iba-opt-out-by-goo...

You can control what kind of data Google is allowed to collect about you from Google's settings dashboard : https://www.google.com/settings/dashboard

If you know in advance that you're about to search for a gag gift, open a new private browsing window.

Yeah, these days I use a private window if I'm searching for anything that would throw off my normal profile. That plus adblock means it hasn't been an issue for a really long time so maybe it's better these days.

I just always found it really annoying when I'd spend a couple of days researching a purchase, and then for the next month I was getting ads for the thing I'd just bought. I don't need one of those any more, I've got one!