My #1 tip is to plan ahead, and Plan To Eat is an online tool that helps you do that! Easily import recipes, put them on your planner, and generate a shopping list. Get a free, 30 day, full-service, no strings attached trial. No payment information is required. At the end of the trial you can subscribe for $4.95/month or $39/year.
(This is an affiliate link, so if you end up joining, I will earn a small referral fee from Plan To Eat.)