I’m good at making to-do lists, but not at completing the tasks listed. I remember one item (find a carpenter) featured on my to-do list for about 5 years – it only dropped off the list when I moved house and it was no longer relevant! After trying all sorts of different things (handwritten lists, whiteboards, journals, dedicated apps), I have now settled on the kanban system, which I came across in an article in the Guardian.
The basic idea is that you create three columns: To do, Doing and Done. You then put all your tasks in the To do column. 
Each day, you choose three tasks to put into the Doing column; once you have completed a task, you move it to the Done column.
The pic shows an early version of my system, using a whiteboard and sticky notes. Since then I have bought a set of multicoloured sticky notes, so my Done column is now a riot of colour with a mass of overlapping notes, which is very satisfying! However, I’m beginning to find it harder to motivate myself to bother to write down tasks. Alternatively, I find myself sabotaging the system by doing a task that’s not in my Doing column.
No doubt there are other helpful systems out there, if you have a good alternative, I’d love to hear about it.