Buying presents for gf's is easy. Flowers are a sure fire hit. Wives on the other hand are a b!tch to buy for. I can no longer get away with flowers as I am expected to do that dort of thing anyway all year round. Also why do things women like always cost way more than male gifts? Its sexism at work and I won't stand for it.
Because women do more shopping than men Funk, and the bastards who do market research have figured out that we'll pay more.
I would tell you that a good bottle of booze and leaving the house with your child was a good idea, but then i remembered Mrs. Funk is pregnant. I'm not a flower person, I prefer them growing in the ground so I can sit near them and get wrecked, so can't advise you there.
You already do some of the cooking which is an awesome gift. If my husband wrote on a piece of paper "I will cook 3 nights a week for 3 months without b!tching" I'd, well, I can't write it, young eyes might see.
You can't go wrong with a GC to a store where you know she shops or, go with her and help her pick it out, "help" her try it on in the fitting room if they'll let you.
I'm a heathen pagan (at least that's what this Russian Orthodox b!tch I used to know thought) but I love sneakily finding out what people like and getting it for them. It provides that evil rush, but it isn't really. This is an advanced maneuver and probably not for dudes anyway.
Sorry for the wall of text.