i want to create a club tourney with most difficult holes to play
Look at holes where you have to hit long irons into the green or have to deal with elevations. Use holes where you're not hitting wedges for the second shot. Stay away from Par3s and 5s, those are holes you can relax on for the most part. You want holes where your second shot is crucial to a good score.
I designed a par 4 course that is a serious test for any golfer in the CC and it's named Misery. The course record is 61 and what makes it hard is that there's no gimme holes, you have to think on every one. This is what it looks like....
I did this before WC came out and I didn't use any Kia holes because of the atrocious green mapping. My goal was to create difficult approaches on as many holes as I could and it worked-there's 18 of them. :)
p.s., You're welcome to copy it. ;-)