Here is another(improved?) method! Inspired by the comments in method 1, and my lovely mother.
Supplies for Method 2
-Sewing machine (or needle and thread)
-Elastic (I used 11 inches)
-Scissors
-Seam ripper (scissors or nail clippers will do)
-Straight pins
-30 minutes of your time
NOTES
-This is a very easy method, even for a beginner. If you don't know how to sew, there are many tutorials on YouTube.
-The only jeans that fit me perfectly are from topshop or barbell jeans. However buying jeans from those places gets expensive fast, and these were incredibly cheap from H&M (2 for 30$). Which is why I'm willing to put in some extra work.
@denisem10743 As someone who has done both methods before, this one doesn't work for me. It works for leggings though except you add the elastic in a loop. I like the darts method for sturdier fabric. I'm currently wearing a pair of jeans using the darts method and it's so comfortable. I used to not have good luck with every pair I alter but I have found that if I buy curvy jeans, then it works. For non curvy jeans, darts have to be added to the front as well to balance the extra fabric. But this is for my own body type.
Now, if there are easier ways to hem my own pants...life would be even greater. Thankfully, more stores are offering short/ankle lengths now.
@denisem10743 .... you genius! You just saved my now-too-large cycling shorts from goodwill - I never considered just trimming out some of the elastic!
@denisem10743 Has anyone tried to see if this work with non-jeans? Like running tights and yoga pants? I have so many pairs that fit my legs but not my waist
@denisem10743 Get a gigantic safety pin (like 3" long) and put that on the end of your elastic to help you thread through the waist! Once you've done that you use it to mark where you want to cut after you do the sizing, and then before you cut the elastic use the pin to fasten the elastic down while you cut off the loose end. That way when you pick up the pants to sew them you don't accidentally slip the elastic back into the waist and have to fish it back out.
@charlie47 This is usually what I do when making an elastic waist band. The problem here is how do you get the safety pin out? You'd either have to cut another hole or somehow unfasten it and then thread it back from where it came. I decided that was too much trouble and just did it without the safety pin. It took me about 5 minutes I think.
@denisem10743 I wonder if you could make a small hole in the elastic about 1/4" from the end and use a crochet hook to feed it through. The hold wouldn't affect the elastic once you sew it into place, I'd think.
@jr492 I think it'll depend on the actual fit. If they're a pair that "fits" but stretches out, it should look fine. If the waist is too big at all times, it'll probably get some wrinkles.
@jr492 Not OP but I did this to a pair of jeans that would stretch out beyond wearability after like 2 hours. Here's a pic of the back on me and also of the waist when not worn so you can see how much elastic I added. Hella comfy!
@denisem10743 Thanks! You were neater overall, haha. I was so fed up with those jeans, I ripped a hole behind the belt loop to thread the elastic and then zigzagged it closed. It's hidden behind the belt loop at least, the darker fabric color helps hide it a little too.
@denisem10743 Thanks for this !! I've been getting pretty frustrated lately trying to find a nice fitting pair of jean shorts that fit both the waist and hips at the same time.