When you first start out praying for the sick, many can get discouraged because they will pray for people and nothing will happen. They always question themselves and say, "I just don't have the gift of healing" or "I guess God doesn't want to always heal." Discouragement sets in and eventually they are contemplating on quitting. Eventually they do. Here are a few tips to counter act the discouragement.
-- I tell people who are starting out doing this that the first 10 to 15 people you pray for aren't going to get healed so deal with it. Of course, there is always the exception to the rule, but set your mind in this fashion so you know it's okay that they don't get healed. When the first healing comes, you'll most likely be shocked because you won't be expecting it. Why does it take this long sometimes? Because demons are fighting your prayers and work hard so you don't see these miracles. They don't want your faith to increase let alone the person get healed.
-- Also, if you're starting out praying for healing, don't go after all the diseases first. Go after all the joint and bone injuries and headaches. When some christians start out, they go after cancer, auto-immune diseases, crippled, mental illness, etc.. In other words, they start off with the severe cases. Nothing is going to sack your faith quicker than to pray with these cases off the bat. Why? Because, most likely they won't get healed because they require more power and knowledge. Now, please understand me. I'm not saying to avoid them. I'm just saying, don't go out of your way to pray for these cases first. Eventually, you're going to want to pray for these, but you want to be able to see healing first so your faith will start increasing.
-- Never approach people on the streets like this. "Excuse me, can I pray for you?" Don't let that be the first thing you say to them. It's too weird for people. Just say, "Excuse me, what happen to your knee?" All you need to do is ask them 2 questions. What happened and how/ when did it happen? You ask two questions so you can establish a brief relationship. It makes the person feel more comfortable with you. Then ask if you can pray.
-- Keep the prayer short, like 15 seconds. Then ask them to see if it still hurts. If it does, then pray again.