Every once in a while I walk around the garden with my handheld computer and add every job that I notice to the todo list.
I have the garden divided in to categories, for instance 'Main Garden', 'Walled Garden' and so on. This is basically so I can organize jobs so that I'm not having to move from one place to the other so much although that's not too important, the important bits are to prioritise and try to work to a due date, all of which can be added to the todo list along with any notes about the job. Once this is done I will usually take the list home and synchronise it with the desktop software that goes with the handheld.
Desktop date book, the todo list is in the bottom right corner so all you have to do is drag and drop the jobs on to the date book and roughly set the time needed for each job. Unless you like to put yourself under pressure its best to leave a few small gaps as jobs usually take longer than you think they will.
I could do it all on the handheld but its easier on the computer. I plug it in and press a button and it all gets syncronised either way. The date book and todo list sit side by side on the computer screen and are displayed in order of due date and priority so its just a matter of dragging the jobs in to vacant slots of the right size in the date book. I then sync the handheld with the computer so that it has the new copy of the date book.
The date book on the handheld replicates that of the desktop.
Of course as you can imagine nothing ever goes to plan so the times often have to be edited as each job is completed so that I have an honest account of my work. The account has to be honest because in a years time I will often refer back to what I was doing last year so that I know not only what I need to be doing at a certain time but also it acts as a pacemaker. For instance because of the snow we just had I can see from looking at the date book for last year that I am behind with work in the veg garden but have time in hand as far as the conservatory and pruning of the fruit trees so I know that this week I need to concentrate on the veg garden. I also know that last year there were two weeks in February that we had snow and ice so if we have no more bad weather I should be able to get back on top of things. So my pocket boss keeps me on track and focused on what needs to be done. These are his two main jobs but there are many more he undertakes to aid me.