My favorite is the Thomas Joseph one. I do it online everyday.

I do occasionally, but I'm not very good at them. I'll look for that one and give it a try.

I do, started back when I worked shift work in La.

Yep, every day. I buy books of the expert and challenger ones. They do challenge.

Do 3 or more a day. Thomas Joseph one is in my local paper. Usually takes ten minutes. For a while I was doing the los Angeles times one and I found that challenging. The New York times one is a real humdinger to do also.
You know they're tough when you have to look up what the clue means.
I hope doing them exercises the old grey matter and keeps it from wandering on me.
Been doing crosswords regularly for 40 or more years. After a while you see a lot of the same clues and your vocabulary certainly expands too

Merl Reagle puzzle costs nothing, Online Sunday. Very challenging.
Google Merl Reagle puzzle, You'll like it.

Local papers every week

The Thomas Joseph one uses a lot of the same clues but asks the questions in a different manner. The more of the puzzles you do, the better you will get at it.

Nope, not smart enough. I can do the quiptoquotes pretty good though.

About once a week.