By using LoA for what you want. If you know you have him, you don't miss him and if you miss him, all your effort of visualising and stuff gets you nowhere. There are two types of missing: The "I have no idea if and when I see him again" type of missing and the "omg, he isn't around for a week, I miss him so much". The latter can even be quite enjoyable at times, because it makes your anticipation to see him again grow. Nothing bad about that, because you expect him to come back. The first isn't so enjoyable and will give you more lack of him. You just have to know that he is on his way back, that's all that's ever needed.