Seems like there are two issues here:
Baulking into gear - usually there is a "baulk" ring in the gearbox whose purpose is to resist the selection of a gear until the synco ring has matched the speed of the selected gears to provide a smooth engagement.
Grinding into gear - caused by (assuming the clutch is disengaged) - brute force shifting, trying to shift too quickly before the synco ring has speed matched the engaging gears.
In either case the answer is in the timing..there is a speed for every upshift that would give a perfect shift even if you had no syncro mesh at all, you just have to practice until you find it. Similar with baulking on the downshift, you have to add a little throttle, timed so that the engine speed matches the gearbox "speed" when you engage the gear (may need to double declutch if the box is cold or extra reluctant).
Last edited by SenorFunkyPants; 06-08-2011 at 08:34 AM.