Sewing silk velvet can be a beast. The one garment that has been in my winter/holiday wardrobe for the past 30 years (in various iterations), is a pair of silk velvet pants, usually black. Take a look at the video to see the easy technique for pleating. I love these soft loose fitting pants; they are comfortable, warm in the cold, cool in an overheated house, I can cook in them, sit on the floor, wear them to a casual family gathering or to an evening event. The pant I am using now I got from Eileen Fisher a few years ago, but you could easily make them. The secret is to allow a bit of extra ease in the pant as the pleating takes up some space, and you want the pant to hang with fluidity.
Pattern Suggestions
On Vogue 9193, I'd eliminate the drop pocket and make the yoke from a soft knit.
Vogue 8499 is has a full cut, do a tissue fitting and/or, make a pre-test to be sure the silhouette is right for you. If the pant is too full, you could go down a size or take it in at the back leg seam.
Vogue 9228 with a soft line and origami hem detail is another design that could take well to pleating.
Vogue 9193 made in Dragonwell Mist printed Japanese cotton.
Katherine and I fell madly in love with the prints we found from a small Japanese designer. Expensive but worth it. I took a cut, but when I held it up to myself, the yellow flower stood out too much. I'd fondle the fabric, then put it back in my stash. One day I had an aha moment and realized I could camouflage that yellow by stitching a patch over it. I used a tried and true pattern - must have 20 pairs of this pant in my closet, so it was easy to place the pattern pieces so the yellow was where I wanted it to be. It helped to have an extra ½ yard of fabric.
I played around with the images on the scraps, cutting a bigger patch, then placing it, then trimming if needed. The stitching is random and was fun to do - I did the stitching while chatting on the phone with a friend and will always be reminded of that conversation when I wear the pants....and I will love wearing them, love love love this print!!!
The fabric with the yellow flower to see the scale and the repeat.