Every time you transplant, you are concerned with these things:
Soil/Medium- it should be fresh, appropriate to the plant's life stage (for example no blood meal in a soil you want to bloom in, or very very little), and with enough lightener to suit your conditions (more perlite if it is colder in your grow or you have had problems with drainage or root rot in the past).
Pot size relative to plant- about a gallon per foot of main stem is appropriate.
Transplant technique- allow soil to get rather dry, support the stem bewteen your fingers with your palm supporting the dirt, upend pot, smack bottom, whole root ball should slide out. If you don't have a root ball, you're transplanting too early. Prepare soil in the new pot before removing the root ball from the old one.
Watering-in- The first thing you do when the plant is in its new home is to give it a nice watering to settle the soil. Use pH adjusted water with one drop per gallon of superthrive if you have it. This reduces stress and gives it a bit of a boost.