Couple of other points missed in the video -
Check that the heater and anti-ice is OFF prior to start. You need all the excess air going into the combustion chamber.
Testing the warning lights is always a good idea.
(Its youtube so....................?)
Nearly all helicopters wil light off before going into the idle detent. Roll it slowly to the point it lights off and keep it there. Some of the bigger 250's and CECO C20/20B's (rare) can be modulated but a Bendix C20 fuel system is on its own.
If you cannot attain the required N1 don't light it. Get a better electrical source.
Glance at the oil pressure gauge before you light it off, it should have some.
Until it is at idle speed, keep your finger on the starter, keep your finger on the starter, keep your finger on the starter, keep your finger on the starter!
If it gets hot, shut off the fuel with the twist grip, keep your finger on the starter, keep your finger on the starter, keep your finger on the starter, keep your finger on the starter!
Not so intuitive to piston jockeys for the first time who are used to taking their finger off the button when they hear the engine make a noise that sounds like it is running.
Fast and hot is the best, anything else is not. Think about the best method of putting your hand in a candle flame.
The 2 minute rundown is to get the core temperature down in the oil galleries in the engine so that carbon does not form and clog the scavenge strut. It applies after flight after achieving flat pitch and is not required if you are only doing ground runs. P.S. each manufacturer/model is different, i.e. 2 minutes on a TM Ariel is detrimental.