I've started taking a long walk (like 7 miles or more) at least once a week. Often, part of it is with company and we talk and then part of it is alone and I think. My recollection is there are some historical figures (writers or what not) who walked a lot as a means to promote thinking. (And I think Ben Franklin was infamous for his long bathes which were a place he apparently did a lot of thinking.)

I have also read that "cool"/unique/brilliant ideas very often are the result of cross-pollination of unusual sets of interests. In other words, if you have two or more interests that don't typically go together, this tends to lead to new insights/approaches that no one else could come up with. So if you are feeling stuck, maybe you should seek out a new hobby/interest, something that seems counter-intuitive to your normal interests if at all possible. My sons have been gradually dragging me into gaming. I was a full-time mom for a long time. I like my kids. They know me well and know how to frame things to make a game sound do-able and appealing to me. They also do a lot of hand-holding. (I used to think video games were the work of the devil or some such. I was not thrilled that my sons were so into games. Now they are corrupting me. This will likely lead to great things. :-P)

Best of luck.