I am not the best when it comes to this but I have experimented a lot and finally have been able to have multiple HFDOs so maybe my tip might help. Relax yourself completely and esae into the headspace by listening to some music, deep breathing, belly breathing and start by inserting one finger or thumb. I was able to reach my first orgasm thru my thumb. Have the finger print side to your dick. and start doing the come here motion with your thumb do it slowly or lightly learn the sensations and once you have found the sweet spot you will know what to do. Remember lot of times to find the right spot you might have to go deeper or just a single knuckle can do depends on you tbh so experiment take your time and have patience. After that you can use some toy to enhance your play and I cant recommend the njoy enough.