Teams need to do a certain amount of upkeep between sprints, and that's what this checklist is for. To make sure you aren't missing any issues you kicked out of the last sprint, or any bugs that cropped up mid-sprint, run this checklist at the end of every sprint period.
To make it easier for yourself, tag issues in JIRA as suggested in this process. Tagging issues "Issues for Next Sprint", "Recently Created Unresolved Bugs", etc, helps you quickly filter the issues so you can see only the vital ones.
This process is linked to another one you can use if you need to, the Sprint Estimation Process.