What is your level of sewing expertise? Do you know how to line something? Make the pants/shorts pattern twice--from the two fabrics you want to use without hemming or adding the elastic (I assume you're doing an elastic waist). The only seam you should have sewn is the crotch.

Turn one inside out and put it inside the other so you have right sides facing each other and the back/front orientation matching.

Sew the waistbands together, flip and push one back inside the other so you now have right sides facing out. Make a waistband casing for elastic, hem and attach the legs and voila!

I've reread this a few times and it makes sense to me, hope it transfers to you as well. I used to make my boys flannel-lined pants for the winter, the cuffs looked so cute on them with those white baby shoes.

Anyone have an easier way?

Here's another explantion of how to do this, but I confess, I'm the kind of person who needs pictures!

This may not be much different from Dian57's instructions.

CMC

Here is a link that might be useful: another explanation of how to do this.