We'd need to see the space and furniture to help much. Comment on this post and upload photos using the Photo button below the comment box.

If there is room the perfect sewing room table is an island...maybe 4' by 8' and approximately waist height..under the island ..shelving suitable for fabrics and baskets of other supplies in the middle ...on the ends under the island build narrow shelving suitable for threads..scissors ...boxes for sewing machine parts..needles..pins...Etc..this gives you a huge space for cutting..pinning.....working all around the table as needed..the corner desk if there is still room can house both your sewing machine and desk area or you can split them up...over the sewing machine is an excellent place for wall shelving for trims...zippers...buttons in jars..and a few decor pieces or just cute things that you love...projects in progress but not finished and so on...then a cheerful color on the walls ...a space to pin inspiration pictures....and good lighting over all work spaces and you are good to go..one of my favorites is a really comfy roll around chair for handwork and sewing on the machine and finally music or a little tv ...this can really all fit and work if you install enough shelving to keep your island clear and free of clutter..tiny narrow wall shelving near the island will also be put to good use I am sure

This can all be as basic as plywood and 4x4'legs with pine shelving....painted playful colors ....or custom cabinetry...