I have used this system for many years at work where new and unrelated tasks arrive unexpectedly every day. It keeps me from forgetting tasks, allows me to track how my time is spent, and serves as a detailed activity log.
Use a full size thin spiral bound single subject notebook. The thick ones weigh more and get tattered before they're filled. You should keep it with you at all times since you never know when new tasks will arise and it takes only a moment to write a line in your book.
On the front cover write the starting date and leave a blank for the ending date. Write your abbreviations on the inside of the front cover in case someone else has to look in it.
Write today's date and day of the week at the top center of the right hand page above the lines. Write only the next step for each task on each line in random order, see below. Skip a line between items if your handwriting is large. Number the items. Keep the cover folded back so today's page is always showing. Keep it in a plastic folder with a clip if you carry it around a lot.
Break each task into small steps then write down only the next step. Begin each line with an action verb like call, write, draw, study, ask, look up, read, evaluate, plan, make, fix, visit, buy, etc. Include phone numbers and addresses. If you can't think of an action verb write "plan". Add new items as they arise, whether they are tasks or incoming information. I use "info" as a first word for incoming information.
When an item is done circle the number; if partly done circle the part. If it generates a new item draw a down arrow with the number of the new item. Incoming information items can be circled immediately.
Each morning copy undone items from yesterday's page to today's page. Undone items are easy to see because their item numbers are not circled. Postponed items migrate upward in the list, increasing their visibility.
Some items require delayed action. Draw a right arrow followed by the future date then circle the item number. On the page of the future date in the upper right corner above the lines write today's date and the item number. On that day, look back at the indicated date and number to see what to do. These reminders are especially good for returning phone calls.
Use the left hand pages for notes from meetings, maps, diagrams, sketches, expenses, calculations etc. The list item that relates should be marked with a left arrow. If notes on the left page generate new items mark them with an item number and a right arrow. If you need more space go to any empty left page; show its date next to the arrow in the item.
As well as keeping you organized, the books are a permanent detailed log of all your activities. Writing progress reports is easy because you just read the activities out of the log for the relevant dates.
When you reach the end of a notebook just write in the ending date, number the front, store it safely, and start another.