Well first of all, that title and this post is really unclear..

I will assume, however, that you're talking about a FR style floating bridge.
Perhaps you should read the FR setup guide stickied in this forum?

I will also assume that you mean tuning as when you're changing strings, since you should only ever have to use the fine tuners once you've put new strings on and tuned them up.

Personally, I just prop the bridge up (I use a battery wrapped in a paper towel tucked inside the cavity under the fine tuners) as I change all the strings and then tune them up.
Then I just remove the battery I used to prop it up and tune the strings again (since the tuning was slightly off from the bridge being propped up).
It doesn't take me much longer than a non floating bridge really.
Maybe 5 more minutes at the most.

If you change one string at a time you wont have to prop the bridge up either.
Things with strings:
Ibanez J.Custom, Prestiges, RG8, SR5 bass etc
LP's, Strat, Tele
ENGL Retro Tube 50
5150 III 50W
Orange Terror Bass
If you mean tuning the guitar once you've put new strings on.. Then you just need to float the bridge. The quickest way I've found to do this is to turn each tuner a half turn without actually plucking any strings..

start from the the low..

E - half turn
A - half turn
D - Half turn
G - Half turn
B - Half turn
E - Half turn
.... repeat process until the bridge is properly floated and leveled, and then start tuning the guitar properly.

As for switching between tunings and stuff, then your best bet is to block the bridge off, I use a tremol-no.
Starting with your low E, tune it about one step sharp, then tune your A sharp but not quite a full step, continue doing this getting closer to the actual correct pitch as you tune each string and finally tune your high E to the correct pitch. That should get you close. This is how I do it, it may not be everyones preferred method, but it works great for me.

Anything you do to one side of a floating bridge, the opposite happens to the other side.
Quote by atza
@ J_W
That's great. Takes a little getting used to it but it works ,Thanks

Glad it helped. It will only get easier the more you do it.
1,6,2,5,3,4, cross tuning is quickest for me.
WTLT 2014 GG&A

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alright "king of the guitar forum"

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nope i am "GOD of the guitar forum" i think that fits me better.

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youre just being a jerk man.

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Quote by atza
@ J_W
That's great. Takes a little getting used to it but it works ,Thanks

Also. always remember that the thicker the string on the guitar, the more it will change tune when you tune other strings. So if you're tuning the A string, the low E string will change its tuning more than the high E. Your bass strings will always give you more problems than your B and high E strings, which usually don't change too much.