If I see something on a site or just want to reply to someone, I use the Send Now option. If it's really awesome content I will also add my post to another queue so that it can be used again.
With the Main Queue I have set up a series of Time Slots throughout the day, so that if I want to share someone else’s content and only want to do it once, and at a time that I know more people are looking at my feed, I just add the post to my Main Queue.
Yes, I have some Time Slots that overlap my Time Slots in the Recurring Queue.
The Recurring Queue has many features, and this is where I placed all the content that I am happy to share 24/7... 365 days of the year... stuff that never dates. If it is an amazing link that expires in three months I will use the Expiry Date option.
With the Recurring Queue you can also download the entire content of your queue back to your computer for safe keeping - as well as modifying it so you can re-upload at a later date.