Let me preface this by saying I am not a lawyer. That said, if you infringe a patent you can be sued. In the US, It doesn't matter if you don't sell the actual product. Think of it this way. If you make something that is patented instead of buying it you represent a lost sale to the patent owner. So my guess is you shouldn't infringe on a patent on YouTube and you shouldn't demonstrate to others how to infringe on a patent.
What you might want to do, however is determine if you are really infringing on a patent. What is protected by patents are often a lot narrower than you think. You should attempt to find the patent(s) in question and read the claims. To infringe on a claim you need to implement each and every aspect of the claim. Long complicated claims are inherently less restrictive than short simple ones. If there is a specific product and patent you are worried about then posting a question about that patent is welcome.