Following are few things we should follow religiously while doing development in an Agile Methodology:
1. Prioritization MUST be done thru proper channel. No new work should be taken without following the process i.e., Stories should be prioritized by PO and not be coming from the sides.
2. Proper Story Grooming should be performed on a regular basis. In helping development team to deliver what is asked
3. Retro should happen on a regular basis, every week (if it's a weekly sprint like ours) to learn from your past mistake. Also, make sure to track what was suggested in previous retro and define KPI on the trend of past mistakes. This will help you determine if you are doing better, worst or no change.
4. Stories should be properly written and documented. No work should commence without having properly written Stories
5. UX deliverable dates should be factored in when estimating sprints. Delays in approved UX will impact your overall delivery of sprint. If possible add a new column to the story to dictate when UX will be ready/delivered