Summarize the following:
Yeast loves nothing better than a warm, moist climate to live its yeasty life to the fullest. If you want your dough to rise, you need to give the yeast what it wants.  Fill a baking pan with boiling water, and set it on the lowest rack in your oven. Place the container of dough on the middle rack, and close the oven door and allow the dough to rise. Alternately, you can boil a cup of water in the microwave, then place the container of dough in the microwave with the water, and close the door. (Don't microwave the dough!) Some people turn on the oven, and place the dough on top of the stove, covered with a damp towel. The oven keeps the surface of the stove warm, and the damp towel provides the moisture. If warm and moist isn't activating the yeast (you'll know in less than an hour), you can try adding more yeast.  Open a new package of yeast, and mix teaspoon of yeast with 1 cup (240ml) of warm water (at about 110°F/43°C) and 1 tablespoon of sugar. Let this mixture proof for about 10 minutes, until it gets 1/2- to 1-inch of foam. If this fails, you will need to get fresh yeast and try again. While proofing this yeast mixture, gently warm the flat dough to about 100°F (38°C) by placing the bowl in a warm place. Adding more flour as necessary: a ratio of 60% flour to 40% liquid is usually a good ratio for bread doughs so add sufficient flour needed to balance. Knead the active yeast mixture into the dough, then let it rise in a warm, moist place.  This can also be an indicator to see if your yeast is not active. This method makes the yeast very active so when it is added to the dough, it should rise perfectly. If your dough still fails to rise, it will indicate the yeast is not at fault: there is another problem. You can also do this at the beginning of the recipe next time you make a different yeast dough.

Summary:
Turn up the temperature. Add more yeast. Blend in the starter.