This is one of the hottest topics within the development team.
Right now we are choosing between 2 most common models:

0% Maker fee and 0.1%-0.3% taker fee (depending on the monthly volume)
or
0.1% Maker/Taker fee

We honestly prefer the second approach (even fees for everyone) because it is much easier in implementation, however, we feel that this may hurt initial volume growth. There is also an argument that Market maker should be incentivized for providing liquidity to the platform. Some exchanges utilize own tokens as a fee-payment option, but we currently not considering this method (simply because we are not big enough at this moment).

Vouchers/Airdrops will remain with 0% fee for a while. We considered to introduce a minuscule fee for airdrop creation but later discarded this idea to encourage token dev to use our platform.