Warning is using mixer means your bitcoin will likely be marked as tainted coins by exchanges and centralized platforms. It can trigger their bots to mark your accounts on their platforms as suspicious and your accounts can break their Terms of Service, AML policy. Your account even can be frozen, terminated by AML violation and you have to think carefully before deciding to use a mixer.
If you don't want to have issue and you don't need too high privacy, you don't actually need to use mixers. Use a wallet software with Coin control feature to control your UTXOs is good enough and no mixer will be needed.
Use both features. The mixer will make your coins private, and coin control will allow you to choose where to spend the mixed outputs best, without inadvertently placing them in transactions that they're not supposed to be in there.
Coin control by itself is not very useful unless you have a specific use case for it, e.g. you have donation addresses that should not be mixed up.
