For me when a task is overwhelming enough that I have been procrastinating on it for a while, or have attempted to start it a few times unsuccessfully, the thought of working on it for a whole hour is usually too much. But I can usually identify some trivial first step and say to myself “I’ll spend 15 minutes on that first step”. If I can get into the task, 15 minutes can easily become hours, at least until I find some decision overwhelming again.