Since the Fedidverse is all connected, should I have one account for accessing both Lemmy and Mastodon or have separate accounts for each one (as I do now)?
I’d say separate. You can only interact with the other instances through your instance, and while they use the same protocol, lemmy and mastodon are just fundamentally different styles of communication that don’t mesh well together.
depends on the server, my goal is to get multiple fedi apps running under a single login system so you can be the same account anywhere.
there is no playbook for this so you have to roll it yourself, the apps do support SSO through systems like LDAP so its entirely possible.
Seperate accounts.
I suggest separate accounts as you’ll have a better and fuller experience. If you want to participate on both with a single account, I hear kbin has that capability.
The instance(s) on which you have accounts dictate the interfaces you use to interact with the fediverse. If you find lemmy’s interface adequate for interacting with mastodon or vice versa, then you only need one account; but if you want to use different interfaces for different types of content, get accounts on instances that offer those interfaces.