Mate if you are learning to operate in the below 500 foot area and first have not covered off low level emergencies including engine failure, then find an instructor who will.
Start at 500 feet zero airspeed, get that lever down, cyclic forward and right pedal right in. First - sit back and watch the instructor- and just study the reactions of the AC while your instructor demonstrates a few.
Watch your RRPM it shouldn't go below the bottom red line, learn when to fairly quickly check back your attitude, I.E. 60 knots please sir not six hundred, watch the airspeed increase, (note you will still have a quite nose low attitude therefore when flaring there is much more angular displacement), the RRPM can thus be regathered quickly, study the initial height drop before you are again in normal auto flight. That will give you your dead mans limitation, make sure if you like your line is longer than that height.
Airspeed always takes the P out of pain. as long as there is a spot in front always, but always go for a bit of airspeed.
With practice you will be able to initiate lower although no need in training to go below 200 feet with a bit of headwind.
It is a matter of practising the technique and always looking for a spot, get an appreciation what sort of brush you can go through with your blades and what you can't. At the end of the day the aircraft is replaceable, always try to keep the airframe headed for an area where it will stay upright..
Practice dropping your line each time, if you can't think that quick you shouldn't be there.
Do all that on an open field.
all the best tet.