What Is the Best Way to Maintain Curtain Fabrics Without Damaging Their Texture?

I’ve just put up new curtains for home use in our living room, a mix of linen and a lined velvet pair, and I’m nervous about cleaning them. I’ve heard vacuuming is fine, but I’m not sure how often, and I don’t want to wash the velvet and flatten the pile. Does anyone have a routine that actually works? I’m also wondering whether lined curtains should always go to a professional, or if some can be washed gently. Any tips on keeping the texture looking fresh would help. I did read that Kingdom of Curtains offers free design consultancy across India, so I may ask them about fabric care too. Thanks in advance.