The first step is to get the bike idling well. Warm up the engine for a few minutes and ensure you're up to temp. Then, adjust the idle about 15% higher than your actual desired amount. So if you want to idle at 1000 RPM, dial it in to 1100 or 1200 RPMs. Adjust the air screws in and out until you reach maximum RPM (drop the idle back down if you start getting over 1200 RPM). Do this by turning the air screws half a turn at a time. If two settings result in the same RPM, opt for the setting that screws the air screw in a bit more (so if 1.5 turns and 2.0 turns both have the same RPM, use 1.5 turns). Now dial the idle back down to 1000 RPM. If you find yourself in a situation where the screw doesn't seem to be doing anything at all, try advancing the ignition timing a couple of degrees and trying again.
That will get your air screw setting out of the way, so now we tackle the pilot system. This is how the carbs work immediately off idle when you crack the throttle. The pilot system is also responsible from the fueling up until around 1/8 throttle setting. A rough indicator of pilot jet size would be how the bike responds when you blip the throttle. If it hesitates or stumbles a bit, you're too small. If the exhaust sounds "tinny" and there is any black smoke, you're too rich. Assuming you're somewhere in the OK range, you can do a more exact test: Take the bike onto the road and take it up to 20mph in 3rd gear. You should be able to hold a constant speed of 20mph without having to adjust the throttle setting. If you find yourself opening and closing the throttle a bit to hold your speed, then your pilot jet is still too small.
Up next is the main jet (skip needle jet and jet needle for now). The main jet is your wide open throttle setting (regardless of RPMs). You can tune this using the standard plug chop method (run WOT for a mine and then check plug color), but I prefer something a little less subjective. The plug chop method is often good for getting close, but to get exact, you're going to need a stop watch.
Get the bike going at a relatively slow speed in top gear. Maybe 30mph? Just to the point where if you crack the throttle open the engine doesn't lug. So open the throttle up all the way and time yourself to see how long it takes to get the bike to 50mph. Repeat several times to get an average time. Now swap over to a smaller or larger main jet and see if your times get better or worse. It's a pain in the ass and it takes a while, but short of dropping a couple of hundred bucks on some dyno runs with a wideband sensor, it's the best method I know.
After dialing in your idle circuit and main jet, it's time to tackle the mid range. Do a series of plug chops and 1/4, 1/2, and 3/4 throttle settings. If you're rich in all three, raise the needle a step or two. If you're lean in all three, drop the needle a step or two. Now... 9 out of ten people (myself included) can't read plugs as well as they think they can. You can do the 30-50 test using partial throttle settings just as well as you can with WOT.
If you're lean or rich on the 1/4 and 1/2 setting but good on the 3/4 setting, this is an indication you need to change the needle jet size.
If you're OK in the 1/2 and 3/4 range but rich or lean in the 1/4 setting, you'll need to look at the size of the cutaway for the slide.
Finally, if you're in a situation where you're lean on one end of the 1/4-3/4 scale but rich on the other, this calls for an adjustment of the needle taper.
All of the above assumes that your ignition timing is correct, you compression is within spec, and the carbs are properly cleaned and synched. If not, then tuning your carbs is mostly a waste of time.
