What are your key learnings while working in Scrum team?

In Scrum ways of working, it's always important to stay ahead of your game but when things go out of your control owing to the reasons you cannot do much about in such scenarios reorganizing your work as a team comes as a natural choice. Mostly things which did not go your way make you learn the most. In this post I'm writing down some general and most of the common learnings during scrum executions:

1. Don't work on fragile requirements as seen quite often, in immatured setup, customer keeps changing business requirements even when stories are in QA which results in rework and hence delays and frustrations within team. Start work once requirements are frozen and detailed enough. Any changes to once baselined business requirements must be dealt with a change request in subsequent sprints so as proper estimates can be arrived at.
2. Avoid too many Dev and QA reloops which results in waste of efforts. Both Dev and QA must have same understanding of requirements so that stories once in QA don't deviate from business requirements expectations which are established during requirements grooming stage. Integrate QA steps within sprints post Dev is done with their set of unit, function and regression testings with desired objectives. More rigorous and proactive testing mean better would be quality of shipped product.
3. Do all Scrum ceremonies without fail with the best industrial practices. Daily scrum meetings with Kanban boards, not more than 15 minutes. Respect of time by everyone is very important.
4. Daily updates into ALM tools must be religiously adhered, to get a grip on burndown happening as planned or not. The corrective measures can only be taken when data is correct and timely.
5. Scrum team members must have a right mindset towards ethos of Scrum. Every team goes through a process of forming, storming, norming and performing so building a solid team spirit stimulates productivity which happens through colocation and continuous communication. If teams are geographically distributed, relevant tools and business practices must be used to build effective collaboration.Do it with agility. Be critical to work at hand rather to people.
6. Scrum Master must quicken the turnaround time of blocker resolution which hampers team velocity. A timely decision must be arrived on stories that cannot be delivered due to blockers and communication must follow to relevant stakeholders.
7. Apply learnings observed during retrsperetros meetings in subsequent sprints with tangible goals explicitly defined. The repeat of certain steps if required must be made available to team through visual reminders readily accessible to them.

In case you have more learnings to add through your experiences, please share in comments on this post.