What's the best way to share a confluence space with clients.

We are using the Extranet Plugin. As all other solutions disclose all users to your clients. With the @mentioning featureusers can guess and find out all other users (and customers) you are giving access. That’s why we decided to pay for the extranet plugin and it works really well as it encapsulates your customer spaces from the rest of confluence.

It depends on what level of access you want them to have. The basic way to do it is by going inside a Space, then Space Settings, then Permission and add the Client you wish to add under a specific permission rule. You will most likely be adding an external client under individual user. Doing so they will be able to comment and upload stuff. Create new stuff. Which should be sufficient. Hope this helps.