I think reviewing defillama to see which UniswapV3 pools on Arbitrum, with a good sized TVL that have good APR helps give insight to what may be the best ones to start with that would generate the most activity for the used incentives.
https://defillama.com/yields?chain=Arbitrum&minTvl=1000000&maxTvl=&project=uniswap-v3
These look promising to start with
WETH-USDC
WETH-ARB
ARB-USDC
These are also being considered and may bring other partnership/marketing opportunities for Flashstake/Arbitrum/Uniswap/xToken:
RDNT-WETH
WETH-GMX
FLASH-WETH