Go to Fyber and look for the "Sky Sports Mobile TV" offer. It's (i think) 258 tokens if you buy a subscription (I say 258 because I had 3 tokens before I did this and I now have 261..).

The best part about it is that Sky are currently offering a 7 Day Free Trial of the service

So once you've selected the offer from Fyber, download the app, sign in with your Sky ID and purchase any of the subscriptions - it will ask you if you wish to take up the free trial offer, so obviously accept that.

The subscription is created through iTunes and will automatically renew after 7 days to a paid subscription so you must remember to cancel.

Obviously I cannot promise that your tokens won't be revoked after you cancel but as it stands, i've just taken up the offer and activated the free trial and almost immediately received my 258 tokens.

Supersonic currently do the same offer but do not choose them as you're likely to never get the tokens or have to wait forever for them after providing a DNA sample to prove you did the offer.