Make the next step visible
A button should describe the thing it does. “Compose enquiry” sets a different expectation from “Send enquiry.” Those few words matter when one opens an email draft and the other would send it immediately.
Give an action a response
After a copy action, show a short confirmation. After a selection, make the choice visible. If something cannot happen, explain why in the same place the visitor was already looking.
Think beyond the pointer
A page should remain understandable when moving through it with a keyboard. A visible focus outline is part of the design. So are readable labels and a way to close a dialog without searching for a tiny target.
Make restraint a decision
Not everything needs to animate. A little movement can clarify a transition, but the content should still work when movement is reduced. The most useful detail is often the one that makes an interaction feel uneventful.