Some bloggers are able to meet every update they promise. For some of us however, the time constraints of running a blog can prove difficult at times.
What can help is a rough plan of where you are going, or what you are going to do next. It could range to some sketches to just a few words, but having a direction will really help you in posting updates regularly. I personally have an ideas book, jotting down several ideas per page, sometimes diagram sketches, sometimes bullets, and occasionally just a word or two to trigger a memory.
If you have trouble meeting your schedule you may benefit from a more strict approach, bordering on a posting regime. Make a list of what you need to get done for the week or month, making it as detailed as you feel you need. Some people tend to do their work in blocks, doing a bunch of outlines at once, and then, at a later date going back and writing all the full posts all at once. Others like to get each post finished before starting another. How you work is up to you, but making sure you do the work is the key.
Effectively having a set of instructions can really help motivate a person, having a schedule can help a person to focus, and get on with the work. But everyone is different, there is no perfect, one size fits all schedule. Some people like to take the weekends off, preferring to work during the week. Some people like to get as much done as possible on the weekend so that they can take it easy during the week. You need to get a schedule that works for you. If you find yourself rushing to get a post out Sunday evening because you haven’t updated all week then perhaps you should either start earlier (duh!) or consider writing less posts. Not everyone has the time to do a daily, or even a bi weekly. I also don’t advocate writing just for the sake of writing – if you don’t have a subject to write about, then you shouldn’t write. [Writer’s block is a post for another time.]
Once you have a comfortable schedule sorted out, and a rough plan of where you’re going, making sure the updates come on time should be easier.