If you are testing and deploying upgradeable contracts you can use OpenZeppelin Upgrades Plugins: https://docs.openzeppelin.com/upgrades-plugins/1.x/
There are step by step tutorials:
- OpenZeppelin Truffle Upgrades: Step by Step Tutorial
- OpenZeppelin Buidler Upgrades: Step by Step Tutorial
As for getting ready for launch:
- Follow this checklist: https://blog.openzeppelin.com/follow-this-quality-checklist-before-an-audit-8cc6a0e44845/
- Review the Coinbase guidelines: https://blog.coinbase.com/securing-an-erc-20-token-for-launch-on-coinbase-68313652768f