Suggestions from years worth of helping customers with this issue. Some have been mentioned
1. Adjust your clutch as tight as you dare. This is at the root of more than 50% of the shifting problems with the 4 speed
2. Remember that this is a ratchet mechanism and when you shift you need to full release the shifter so that it can ratchet to the next gear.
3. A miracle clutch can help because the do not drag as much as a 4 speed clutch.
http://store.royalenfieldusa.com/maintenance-repair/clutch/royal-enfield-miracle-clutch4. Make sure your chain is properly adjusted as it can interfere
5. Have someone hold the bike up and look up between the left hand engine case and the inner primary cover. Operate the shifter and make sure that the mechanism doesn't foul the frame. DO NOT do this with the center stand down as it will appear that you have a problem that you do not have. It is fouling the answer is a grinder.
6. You will never eliminate all of the false neutrals, we used to say that we had a neutral for every gear.
7. Get in the habit of using the neutral finder, It is a great help
8. At stop lights keep the bike in neutral not in gear with the clutch pulled in. The four speed can heat up easier than the other transmission's.
9. Consider a bushing kit
http://store.royalenfieldusa.com/maintenance-repair/transmission/4-speed-bushing-kit or a right hand shift kit.
http://store.royalenfieldusa.com/maintenance-repair/transmission/right-hand-shift-kit-110 Use instruction found on the net or this site for adjusting the butterfly plate inside the outer cover. Do this AFTER you have tried the other stuff as it can be tedious.