Firstly, you need to have your SMOKE token. You can get this in a number of ways such as holding a Dormant Dragon and claiming it's SMOKE. You will then need to bridge your SMOKE to Polygon. The Polygon bridge can be found here. The bridging tutorial on YouTube can also be found here.
Once you have SMOKE on Polygon, you can go to stake.dormantdragons.com and connect your wallet with either MetaMask or WalletConnect. You then chose the amount of SMOKE you would like to stake and complete the transaction.
SMOKE balance UI.
From there you will then start receiving SMOKE rewards. Since gas on Polygon is so low, you can claim and then restake your rewards for a very low cost.