Warm up your voice. It's essential to warm your vocal muscles so that you don't strain them while belting out gospel songs. Begin by inhaling and exhaling slowly and deeply. Allow the air to pass across the back of your throat. Open your mouth as wide as possible and say "ahh" for a few seconds. Move on to blowing "raspberries." Purse your lips and blow out, don't use your tongue. Spend two to three minutes on these rudimentary exercises before singing major scales. An easy way to remember the major scale is to follow the "do re me fa so la ti do" pattern. After each scale, start from a higher note.
Stand and breathe correctly. Gospel calls for a high degree of projection. Relax your shoulders and keep your spine straight. Position your feet so that they are shoulder-length apart. Project your voice from the diaphragm, not from your chest. Inhale deeply before each measure and gradually release the breath as you sing. Use each rest in the music to take another breath in, but don't gasp.
Practice in groups. Although there are occasional solo performances, the majority of gospel is performed by choirs. If you aren't able to attend choir practice regularly, gather with friends and practice your favorite gospel songs. Pick a selection of three of four sings to practice each session. Swap parts during practice. Learn your own part but expand the range of singing techniques you use by singing other people's parts.
Control your vibrato. Your vibrato is part of what defines your vocal style, but it's easy to over-do it. Let your vibrato naturally inflect the end of each phrase. Don't force vibrato into each phrase. During solo practice, alternate between adding vibrato to your delivery and singing with as little vibrato as possible.