This might seem strange but as a social media manager, I don't schedule my own posts anymore.
I've got the time, I've (usually) got the ideas and it would make things quicker but I don't use any scheduling tools to automatically send my posts out.
Instead I'll write out some posts and save them as a draft.
The reason is that sometimes I write something and...
- I'll feel differently about it the next day - I've written it when I'm tired and it's nice to proof read before it goes out - Things happen in the world and suddenly that post I've scheduled isn't appropriate or relevant anymore
Scheduling is a brilliant tool, but if you aren't confident about bulk scheduling your work, getting a bank of drafts can be a good alternative.
When you're in the mood to post, have a look at your drafts and see which one feels right.
Edit it abit, play with the words and send it out! Much easier than writing from scratch.
If you've got a spare hour today have a brainstorm of your customer's problems and how you can help solve them with your posts!