Whack them in a tumble dryer on a hot setting: The best way to get your jeans super tight again is to pop them in a tumble dryer straight after the hot wash. Leaving them out to dry on a washing line won't have quite the same effect. Make sure you dry them on a hot setting so that fibres become constricted and snug.
Wear a thick layer underneath: Simple yet effective! Wearing thick tights or leggings under your jeans will make them feel snugger. The type of long johns you may wear skiing are ideal but this method is only effective in colder months.
Use chalk to trace them out: If you're feeling crafty and up to a bit of DIY, this method will work wonders. Simply turn the jeans inside out, flatten out each leg and lay a pair that fit on top, lining up the outer seam. Using a piece of chalk, draw a line exactly around the jeans onto the baggy pair then sew along the chalk line. Do this on the other leg, too, and you'll have a brand new pair of jeans to wear.
Sew elastic onto the waistband: If it's the waistband that's too loose rather than the legs themselves, simply sew a 6-inch piece of elastic onto the waistband at the back of the jeans. You can buy one in your local fabric store.
IF JEANS ARE TOO TIGHT
Spray them with lukewarm water: If you can't squeeze into your favourite jeans after a week of overindulgence or the day after you've washed them, then this trick will work wonders in seconds. Simply lay the jeans out on the floor and spritz them with lukewarm water. Then literally stretch them out by placing your feet on the ends of then and pulling the other end with your hands.
Do some exercise: Pop your jeans on - if you can - and practice some yoga moves, stretches or simple lunges to stretch them out.
Sit in a warm bath: As bizarre as it may seem, make yourself a warm bath - ensuring the water isn't too hot - and sit in it; this will help loosen the fabric.
Remove the waistband: For a more permanent fix, rip the seams of your jeans 2-3 inches and cut out the waistband. Replace this section with a small piece of leather to expand it.