If it was me personally I would save the miles and use them for a longer flight. I currently have around 80,000 which will get me an upgrade from business to first across a flight like DUB - DXB - PVG or SIN whilst still having 30,000 miles spare (currently pricing flights from DUB - PVG)

It's a nice touch having access to the first lounge etc.
An easy way of upping miles is going for an Elite credit card. I put every day purchases on mine and pay it off in full every month.

Upgrades for long haul flights are around 50,000. First spend bonus can be anywhere from 10,000 - 20,000 miles just like that which is fantastic!

Sorry if I'm putting you off short haul first but that's my own personal opinion to save them.