Stability and patience as already mentioned is key, I’m 5 years into this hobby and only now I’m successfully keeping SPS corals.
I’ve got a 8gallon nano, keeping mine stable is an absolute nightmare! The smaller the tank, the less ‘easy’ it is to stabilise parameters- don’t let that put you off though! I had many people try put me off going into the hobby.
And here I am today, keeping SPS corals.
All the very best

- and remember, have fun with it! There was a time that I got so caught up with ‘ideal numbers’ that I drained the enjoyment out of it.
All the best
Emma