As an avid watcher of Gardeners World, I follow Monty's advice. I planted some early sweet peas as per his trial. I have them in the green house. Nipped out the growing tips as suggested, but they have grown away like mad. Going to have to put them into a large pot and stake them. Unless we get a really severe frost, won't need to put any in later this year.
The other thing I tried was the daff's in the bottom of a large planter, filled in and added crocus higher up. Unfortunately, because of this incredibly mild winter, the daff's have started to come up past the crocus! Although the crocus in the pot don't look like flowering yet, the naturalised ones in the garden are - as are snowdrops.