Well you have to be unpredictable more than anything. Realize that just because it's your main hand (if right handed of course) it's probably not being thrown with everything. Keep your left close, make sure to move your head and dont forget its not a sin to slip and move your feet. Be swift and keep it tight. Use your feints, establish a jab, etc. that's the basics. Just a matter of how competent you and your opponent/sparring partners are. Don't know what kind of relationship you have at the gym, but ask around, use it in sparring ask what's giving it away with your coach/trainer or partners if youre cool like that. Of course if youre very observant of your body and movements you can find a what point of your delivery it's being tracked and tweak from there like you do any other punch. Do NOT over extend or stick your head too far out. It comes with time, don't worry. Its okay to make mistakes.
No line breaks...dont know if theres typos this is on my phone so...sorrryy