I've been doing handrails since...about 1988 or so. The first one I ever did was 3-stairs. The longest was 14. The trick, like anything else, is to work your way up to them. Start trying to slide higher and higher ledges and flat rails. Then find a short (i.e. 3-stair) and low handrail, and start with that. The thing that is actually kind of weird, is that shorter rails are actually harder
to do than longer ones. The reason is that you have to ollie much higher to get onto a short rail. With longer rails, you ollie out
to them, rather than up
And one other bit of advice, wear a cup.