You could create a custom perspective called something like “Procrastinating?” that shows all remaining actions grouped by the date they were added.
In this example, I have filtered out items that have a defer date (to deal with repeating actions such as “Water the plants” that may have been added years ago), those that are contained within a Templates folder, and anything that’s a project or a group.
You’ll end up with a list that looks something like this.
You can focus on what was added more than a year ago, deleting anything that’s no longer relevant, and working your way up.
As you go through this process, identify those actions that are not really discrete actions. Add clarity and split them into multiple actions and create projects, as necessary. It’s also a good opportunity to get rid of anything that is technically doable, but not the best use of your time and attention (side note: in the upcoming OmniFocus release you’ll be able to drop these actions instead of deleting them so that you maintain a record of their existence).
There may also be actions that aren’t really actions (e.g. ideas, reference material) that are better stored elsewhere (e.g. Notes or Evernote). You can take this opportunity to move them out of OmniFocus.
You may want to add a tag such as “Procrastinate” to actions that you intend to complete but have been putting off. You could have a repeating action that prompts you to complete at least a couple of these each day.
I also recommend having a repeating action that prompts you to review the “Procrastinating?” perspective regularly (perhaps once a week).
I hope this helps!