There are services like Lido which is live, and RocketPool which is launching soon. You can essentially just buy lido staked ether (steth) on uniswap, steth is a token which represents staked ethereum and accrues interest via rebasing.

RocketPool would be the preferred method once it is live as it maintains the decentralised ethos letting people run rocketpool nodes and anyone pool any amount they want, like how mining pools work today (except running on a raspberry pi, rather than maxing out gpus).

You can stake directly if you have 32 ETH. There's also at least one decentralized staking pool being worked on, but I don't think it's live yet.