dont shift to first unless you are completely stationary, the synchros just dont like it in the zed at and kind of speed. besides there is really no need to be in first other than moving off anyway, its a torquey enough engine to use 2nd everywhere.
the only way to smoothly shift down to first if you really really wanted to would be to double clutch. clutch down, take out of gear, clutch up, blip throttle to spin up engine AND gearbox to correct rpm, clutch down, select gear, clutch up. makes an exceptionally smooth downshift when done correclty, it removes that lurch where the transmission plays catch up with the wheels and engine. also and most importantly it saves your synchro from taking the heat doing this.
avoid block shifting, this takes its toll on synchros too. ideally shift through the box like a sequential shifter does.
don't lean on the gear stick to force a gear in, you are basically leaning on the synchro ring forcing it to match the speeds quicker than it is able. all this does is heat it up and burn it out. If it doesn't feel like its going to go in, you are selecting the wrong gear for the job or your revs arent matched correctly. on the same principle dont hover on the edge of a gear just before it goes in, you might be able to hear a whine at this point, that's the synchros, and you're going to break them.
Get some good oil in the gearbox too, that can make a difference in the wear, also changing it can flush out swarf etc.
hope that helps