Having a series of smaller tasks to do makes your project less daunting and allows you to complete something when only a short period of time is available. This gives a quick boost of satisfaction from the accomplishment which serves as encouragement to do another task.
The hardest part of any project is starting it. The second hardest part is continuing it to completion when the project stretches over an extended period of time or requires intervals of waiting between stages. To tackle the first part, I suggest to get everything you need prepared for the project before you start. Chopping and measuring all the ingredients before you cook makes for a smoother and more pleasant cooking session, and results in fewer forgotten steps and missing ingredients. Same goes for other projects. I also suggest to trip over your to-dos: use the space you will need for something else in the near future, which will constantly remind you of the project you have on-the-go.
To continue making progress on a longer project, split it up. For example, say you want to make printed paper invitations for a party, that you would distribute to your playgroup. You need to (a) come up with the wording; (b) decide on the recipients; (c) come up with the design; (d) assemble the design and wording; (e) print the invitations; (f) distribute the invitations. Each step by itself is well defined and not very difficult. Most of them are not time-consuming either. You can come up with the wording while taking a shower, or breastfeeding, or cooking, or at any other time when you have a few minutes to think. Jot it down and you have completed a task. Deciding on the recipients can be done in a similar manner. The search for the design could be as simple as opening up your software of choice and selecting the colours of the background, the text, and the font. Perhaps you decide to add an image in as well. Putting in the wording and tweaking the appearance will complete the most difficult task (especially for those of us who are perfectionists) since it requires the most creativity. Printing is trivial. And the last step is remembering to bring the invitations with you, which you can assist by putting a reminder in your calendar.
Once you complete the first small task, the ease of success will fuel you desire to take on the next task, to get more accomplished and finish the project sooner. Each task will bring you closer to the end, serving as motivation for the next task. It does not seem like much if all you have done on your project in a day is come up with some names and a few words, as we would in the example above. However, once you realize that it brings you two steps closer to completing the project and is about 30% of the entire work, it will feel a lot more relevant and rewarding.