I wouldn't qualify as an "expert coupon". Instead I have a lot of experience of what works and doesn't - for me.
1. Must match ads with coupons before going shopping
2. Look online for coupons for staples and items we don't have coupons for
3. Shop sales and buy bulk and have a plan/recipe to cook and freeze any perishables or meats
4. MEAL PLAN - according to what's on sale. Check recipes to ensure I have all ingredients. Quick meals, slow cooker recipes and parlaying a "whole chicken" into multiple meals for the week are best.
As far as coupons go, they are my lowest priority. I find that sometimes coupons only apply to some of the most expensive products so shopping a cheaper brand or one on sale is a better cost savings. I don't have a lot of time to save up coupons, keep track of expiration dates and pull them out for every shopping trip.
Instead I focus on ones where I can save .50 or more per item and/or save money on things I'm already going to buy.
Places like Aldi have cheap cookies, crackers, chips and things for kids lunches. Better than spending extra money at the stores esp when I feel rushed. I go maybe 1x a month and stock up.
I hope this helps you!