For me I practice sitting meditation, walking meditation, and yoga. Creating art, painting and photography, are also both highly meditative experiences that I enjoy immensely.
I've made great effort to meditate while coding, but I have found it to be nearly impossibly as my mind needs to change its pace in order to solve problems. Keeping with mindful breathing while coding is possible and very beneficial.
One of the greatest benefits of meditation, as you mentioned, is for problem solving. Solutions come when you 'allow' them to. Walking meditation is very effective for this. I keep a timer and take a 5 minute walk for every 25 minutes of work.