the chain would be my first look and then maybe the clutch play (on lever) otherwise try this, when you are thinkin of shiftin but before hand place some upward pressure on the gear lever then clutch and i think you are going to find it move upwards better, if not the other suggestions are all good.

2007 Speedmaster and miss it! 2013 T-Bird Storm and Luvin it! Catching a yellow jacket in your shirt at 70 mph can double your vocabulary