Signature Lab is a free, open-source byte-signature maker for x64dbg and x32dbg. Select an instruction, press Alt+Shift+S, and get a signature that survives the next update. It wildcards operands, checks that the signature is unique across the whole module, can build reference signatures, and outputs every common pattern format.
To install, extract the zip into your x64dbg folder, the one that contains the release folder.