Get a good book - Singer Sewing for the Home, or Sunset's Curtains, draperies, and Shades. Both have excellent directions and should be available at your library if you don't want to invest.

Thank you, clt3. In fact, I had thought about getting a book but did not know which one to get. I will look into getting one of those.

I would also recommend purchasing a pattern (Simplicity,McCalls etc) for your valance. It will provide the shape of the valance and instructions such as measuring your windows and how to adjust the pattern to fit your windows. Once you have a pattern, we can offer advice on instructions. Patterns can be expensive so download a coupon from JoAnns.

Check on line...lots of websites and videos to help.

Here is a link that might be useful: Simple window valance

Hi Cat11, I am a professional drapery designer/workroom. I would put in 1.5" double hem on the sides, hand stitched or using a blindstitch [ or even very good iron on adhesive]. I would put a 1/2" seam at the bottom, lining---face fabric right sides together, then when that is done, slide the lining up to create about a 1-1.5" hem of the face fabric showing on the reverse side. Then cut the excess lining even with the face fabric at the top.
` put the bottom hem/seam in first
`then the side hems
` then finish off the top rod pocket or what ever
Hope this helps. email me whenever you have any ?'s.... joanbauer@verizon.net Joan

Thank you all for the help, especially to you, gingertopjoan. I just wanted to know what those of you on this sewing forum ( who I know are experienced in sewing), usually do and you, gingertopjoan, were thoughtful enough to answer my question! Thank you! It also is so very kind of you to offer your help! I am going to follow your suggestions.

Also, thank you AnnieDeighnaugh for the link to that video instruction. It too was helpful.

don't hesitate to contact me when you have any more questions or need advise/help; it is my absolute pleasure to pass along my knowledge to you and any other new sewists!
Joan