i.e. before merging a feature branch, always rebase it on the tip of the integration branch, then merge it in with --no-ff to record an explicit merge commit on the integration branch, even though a fast-forward is possible. This gets you the temporal straightforwardness of rebase while preserving the fact that there WERE feature branches and their commits are partitioned in history.
Yes, --no-ff merge after a rebase gives a clear indication that's a feature merged from a feature branch. It's easy to cherry-pick it to another branch (for example for a backport to an old version), easy to bisect this branch or remove the entire feature.