Writing practice. The more you write, the more ideas will come to you. Be experimental. Try to cover a broad range of topics and to write about things that make you a bit uncomfortable, either intellectually or emotionally. Remember, a writer's notebook is a private place and also a safe place. You can explore things that you might not do otherwise and from taking those risks you will have new insights and ideas.
Do other creative stuff: play an instrument, paint, garden, bake cakes, knit, build boats, design monster mutant robots. You will be using the right side of your brain and feeding your writing. It will give you new things to describe.
Make a creativity box. This is a really simple one, especially if you are short of time and energy. Get yourself a box or folder - if you can find something that gives you aesthetic pleasure so much the better. If you feel inclined, you might taken an old shoebox and spend an afternoon decorating it, making it special. Or get your kids to decorate it for you. They might want to do their own as well - encourage them. This is fun to do in its own right and helps you not take the task of gathering ideas too seriously.
Every time you have a random idea, an image, a situation, an observation, jot it down on a piece of paper and put it in the box. You might see a photograph in a magazine that inspires you, or read an article that sparks your imagination, so clip the article or print out the web page and put it in the box. Once it is in there you know it is somewhere safe. You don't have to consider whether you have filed it under the right heading. Indeed, the very randomness of this way of collecting material is desirable. Later on you can then review what you have accumulated and look for the ideas that you find most intriguing, much as you might review what you have written in your notebooks. You might also use the whole thing as a lucky dip for when you are looking for writing practice topics. The important thing is that if you have a physical place to put those fleeting ideas, then they will gain more substance in you mind as a result. If you are feeling that you have no ideas you can get out your treasure chest and reassure yourself.
Practise relaxation and creative visualisation. There is lots of material out there to help with this. Personally I found www.hypnosisdownloads.com really useful and not at all expensive.
Take a 'creative holiday' to feed your ideas: go to art galleries, concerts, a different part of town. Take a notebook and observe and write down what you see and feel.