The Happy Place is brilliant for keeping you calm and relaxed during stressful times but if you need to achieve something specific, something that is difficult or painful, then you need a different kind of visualisation.
If you need to achieve something physical then it helps to imagine a scenario that links closely in with your aim. Here is an example:
Two years ago I had to have intensive physiotherapy to treat a frozen shoulder. I couldn't get my arm even to shoulder height and it turned out that my shoulder blade was completely cramped up and immovable. The main treatment involved the physiotherapist pulling my arm out to the side with his whole weight as I lay on a bench. He asked me to relax so he could pull the arm out as much as possible.
To help relax the right part of my body, I imagined my shoulder joint as a metal coiled spring, completely rigid and unmoving. As the physio pulled, I gradually made the metal spring turn to hard rubber, and then softer springy rubber that started to uncoil and lengthen. It was all very slow and fluid in my mind and I concentrated on seeing the coil and noticing the detail of the material changing and the physical properties of the material. These matched what I needed my arm to do. The results were excellent.
Next time I'll look at the pros and cons to visualisations commonly recommended for use during birth.