i have a slightly different toss for each serve...:
flat: overhead, more in front into the court
top: overhead, less into the court, swing more up and down
kick1: left of head, less into the court, swing more up and out to the right
kick2: overhead, less into the court, swing more up and out to the right
for kick, ideally all my tosses are more into court, where i'm launching my self up and into the court... ie. on perfect tosses, where i'm able to push up and into the court with my legs, all my kicks land around a foot from the service line, and hit the back fence on a high arc,... but i think there's less margin for error (ie. toss needs to be perfect to match my lean) - ie. can't replicate this all the time.
as far as how to get a consistent toss... alot of practice. my toss is still not perfect. i spent an hour yesterday practicing 2 things;
* keeping my head up at contact
* experimenting/practicing a consistent toss...
IMO it's a simple motion (fine motor skill) that the pros look easy, but is not (ie. given the other moving parts - ie. loading various power sources, and given the smallish target area you need to toss into)... in general, when my toss is ON, my serve is automatic... 95% of the time my serve is off because i'm spending all my time adjusting to a bad toss.
side note, there's a guy i know that played high D1, and his toss is all over the place (like 3.5 level toss)... he admitted that he spent alot of time getting good at adjusting to a bad toss, and he was unsuccessful at developing a consistent toss because he found it more difficult.
my $0.02