[osivertsson]

Split work into small enough tasks that they are all max 1 day if at all possible, meaning that everybody on the team knows what should be done and can just "go-go-go". Much easier to estimate.

Always remind yourself and your team about any work ouside the core functionality being implemented. Database migrations, deployment costs, documentation needs, unit- and functional tests (both updates and new), technical debt that needs to be fixed now, and if there are other risks like hitting resource limits or missing performance targets.

Keep track of actual outcome vs estimate. What was the main reason it took longer? Best done if working close to co-workers on tasks, making progress or lack of it associated with the team and not individuals, where it could easily become a blame game.

Be aware of how much distractions you have from doing actual development. Meetings, urgent bug fixes or help with other problems in production, customer contact, supporting sales, etc.