Write them down!
If you have a daily plan established (please see "The 1-6-10 Rule", print it out at the start of each day (or better yet, at the end of the previous day!).
If things are starting to get you down, make "Opening the Mail (bills, etc.) the only task you HAVE to get done today. Not because you owe them money (although that's a good reason) but because it is dragging you down and sapping your enthusiasm.
Write on a small card "Process Mail".
At the end of the day, take the card to bed and examine it.
Did you achieve your objective? Did you open all the mail, draft the letter, file the papers?
If so, sleep well.
If not, ask yourself WHY you didn't open the mail etc. determine the stumbling block, and make THAT your top-priority for tomorrow, and go to sleep feeling good about THAT!
The key here is to WRITE IT DOWN (yes, I'm shouting this at you!).
Write it down so that you have a solid tangible record of what you expected to achieve.
Measuring what happened is the vital link between saying you'll do something, and making sure that the next time it really gets done.
Try it and see!