If he respects your cues and space and shows signs of submission I'm pretty sure you're doing it right. One thing that made my horse more comfortable coming to me was doing join up in a paddock instead of the round pen. It took more energy, as the paddock was bigger, but with time he wouldn't even run around the whole paddock, he would run in a circle around me. I think an open space made him feel safer to take a chance and approach me and more natural to him, since he gets all day turn out every day. Now he comes to the middle in the roundpen too. If the paddock doesn't work, I think you should just keep trying. Sometimes, with horses, you try on and on to get an exercise right, for example, and it never works, and suddenly one day you find the right "button" and it does. Every horse has different buttons, so keep trying and you will find yours'.
Yes he does let me touch him. In response to Sofia he does drop his head & show other signs of submission. Would be able to suggest any testings I could do to make certain that I am doing it correctly ?
Sorry, I have to disagree with Debby. I have done join up with my horse and other horses several times and seen friends do it and the result is amazing. I'm no expert though, but the same thing happened to me when I started doing horsemanship with my horse, and he wouldn't present any of the relaxation signs or come to me for anything. With time, he started to do that and now I barely have to do anything and he will come to the middle. I guess some horses are just more suspiciois than others and take more time to trust. The first ever time I did it with my horse I was doing it wrong though, and he was literally playing around, so make sure you are doing it right as well hahah