You mean a kick serve ?
This is the serve I use for my 2nd serve. My 2nd serve is highly consistent although slower than I'd like; over 70 mph. But my placement allows me to usually bring a player out a bit to compensate for this slower pace (I can hit it harder but get lazy on 2nd's; my first serve is smoking)
Aim for 7 O' Clock to 1 O' Clock to maximize
I use an Eastern Grip on my second serve.
And most importantly; while serving properly ...
Have confidence. It will land in.