The wallet UI should do that for you automatically. Wallets which reuse addresses have been a constant source of privacy breaches and even lost coins (is it iota where you can lose coins if you use the same address as few a two different times?)
Most wallets these days don't reuse addresses, but without mixing, confidential transactions, or another approach, it's trivial to cluster a wallet via its chance outputs, etc.
Iota is/was incredibly broken, and shouldn't be used as an example IMO.
