I think the answer will vary depending on who you are trying to hide your bitcoin from, or in other words, to what extent you want to enhance your privacy:

 - If the purpose is to hide it from your girlfriend/children/your small community/internet hackers, then using bisq or https://exch.cx/ will be sufficient (BTC ---> XMR ----> BTC.)
 - If the purpose is to hide it from the government or the IRS, it is better to be more careful, and this step may not enhance your privacy much.
 - But if the purpose is to hide it from a government agency that has sufficient resources to track you, it will definitely not help you.