Originally Posted by
DOHCVTEC
if it is caused by incorrect revs you can try the following double declutching:
1. put it to neutral and let off the clutch pedal,
2. blip the throttle to rev the engine up a bit,
3. push clutch pedal and engage 1st gear.
'
This method will let you get into 1st gear smooth and fine even if u're going 40km/h, as long as your revs are below the 1st gear's max allowable speed. It will also prevent / reduce wear on ur synchros.
check your transmission oil first, as it's usually what's causing this problem.