Simple things may be the most useful ones!
Scrum Master is a facilitor of Scrum team. In meetings, by using useful stuff he can support team to visualize better what the team is thinking/discussing. So that the collaboration and productivity of team through activities is getting improved.
To make team life much easier & more efficient, we developed an Scrum box where they can find planning poker cards and other supportive tools to improve the effectiveness of team meetings. The magic toolkits were delivered to all our teams to use in their daily Scrum.