Seeking tips on how to give painless intradermal injections

I have a new job at allergist's office, and I will be the only nurse. I am afraid that I am not very good at the intradermal injections. I have not done very many of them before this job. I have done a few TB tests at a previous job. I have no problem getting the wheal, but I am afraid that I am hurting the patient, once I inject the allergen. I practiced at home, one injection on my daughter and one on my son. They were both fine with the wheals, however, once I injected the saline, they said that it burned. What am I doing wrong? Being on the receiving end of tb injections, I have had some that burned, one that actually was sq, and I have had a few that were absolutely painless. Please, if anyone can offer suggestions on giving a painless ID injection. I have given many SQ and IM's with no problems, but I can't get the hang of ID's. And, I have to do many of them for the allergy testing. I just don't want to hurt anyone. There are too many injections for one patient. I even tried the injection on myself, and it really burns once I inject the saline. I let the alcohol dry, too. I have done about 4 tests. Actually I think my first two tests were better injection techniques. At least, my pts. said that they didn't hurt too bad.