Have you tried this hack? Works for jeans thats are very loose at

Life Hack: How to Button Tight Pants

Jeans Alteration: How to size down Denim Jeans at the waist

I tried the no-sew, adjustable jean buttons for waistbands

How to Patch Stretchy Jeans : 5 Steps (with Pictures) - Instructables

Jeans Alteration: How to size down Denim Jeans at the waist

Want To Save Your Favourite Jeans? Try These Easy Sewing Hacks

how to fix your jeans waistband {no more jeans gap!} - It's Always

I Have to Buy New Jeans. Help! - The New York Times

Jeans too loose? Try this hack, loose jeans hack

How To Stretch Out Tight Jeans

Baggy Jeans: Styling Tips + Outfit Ideas - The Mom Edit

The Secret to Breaking-In Your New Stiff Jeans - The Mom Edit

This Genius $6 Styling Hack Makes My Jeans Fit Perfectly Every Time