How can I paint the skirting board without any getting on the carpet?

Use a strip like this to hold down the carpet and pull it away from the baseboard while you paint with the other hand.

https://hydestore.com/hyde-tools-45005-paint-shield-15.html?fee=3&fep=1472&gclid=EAIaIQobChMI6-qj_ZD63gIVCx-tBh0mEwkqEAQYAiABEgJPD_D_BwE

Tape it off. I typically use a cheap plastic tarp to avoid spills and drips.

Secure a paper drop cloth to the floor with 2-inch-wide masking or painter's tape. If you're painting an entire room or a carpeted area, consider covering the floor with plastic sheeting, and then topping the plastic with a canvas drop cloth, which is far more durable and will absorb paint splatters.

Use a piece of cardboard to hold the carpet down around the edge so you don't get paint on it.

Hi Mike. I use a drywall trowel to hold the carpet back while I paint that area and just work my way down. You could also tape the carpet back with painters tape.

Thanks for all your suggestions. I'm sure to find one.

I've also used a poster board trimmed with painters tape (since paint will soak through paper). It worked well. Good luck!