When trying to get past a writing block or a brainstorming lag, take at least ten minutes to sit down and write. Force yourself to write for the full ten minutes, no matter what comes of it. The act of putting pen to paper will  stimulate the part of your mind that generates ideas. Mind mapping is a brainstorming strategy that allows you to map out different tangents of thought to stimulate new ideas. Get a piece of paper, poster board, or whiteboard and write your goal in the center. Write subtopics and related thoughts around the goal, and continue branching out from them to develop your train of thought. For example, a mind map about the environmental goal "Going Green" could branch into subtopics such as "Reducing Waste", "Eco-travel", and "Global Warming". For a fresh perspective on a topic, attempt "rolestorming". Picture yourself as someone else (e.g. a parent, friend, colleague, or partner) and imagine how you would approach a scenario as them. You can extend this brainstorming technique to famous people or historical figures (e.g. Albert Einstein, Bill Gates). To open your mind to new ideas, try meditation. Find a peaceful place to sit quietly and focus on the question at hand (e.g. "How can I promote my new business on my limited budget?"). Bring a pen and paper to jot down ideas, and meditate for about 30 minutes, or until a good idea comes to you. To avoid worrying about the time, set an alarm on your phone to signal the 30 minute mark). Remove the limitations that may be hindering your brainstorming progress by approaching the subject as if there were no obstacles. While this process may not yield feasible solutions right away, it will open your mind to possibilities you would not look at otherwise. For instance, when planning a surprise party, you might overlook certain venues because of financial constraints, such as an expensive French restaurant that your friend would love to try. By allowing your mind to go there during brainstorming, you might get the idea to simulate the restaurant and meal for a house party. Group brainstorming sessions can allow you to develop your thoughts by feeding off of the ideas of others. If you are working on a group project or collaboration, schedule brainstorming time in a quiet location with few distractions. If you are working on your own project, ask friends or colleagues if you can bounce ideas off of them and get their input.
Try blind writing. Make a mind map. Attempt "rolestorming". Try meditation. Remove limitations. Discuss things in a group.