I have some low growing Gaultheris which have red berries and are good for shade. In the same border I have Tiarellas and Heucheras - they grow quickly and are readily available. They have small flowers held high above the foliage. Lots of varieties. Pachysandra terminalis is also in the same border - small white flowers above bright green foliage. I'll put a couple of pix on to give you an idea. There are lots of Euphorbias which are quite low growing and many aren't fussy about sun or shade. Euonymous are useful foliage plants for sun or shdae - green and cream or green and gold varieties. They get to a reasonable size but you can easily trim them back if they get too big. If the soil's not alkaline you could try some of the dwarf rhododendrons as they will take a while to get big so wouldn't take over quickly.
This pic shows the Gaultheria (with the berries) and there's Euonymous behind it - green/cream foliage:
this is a Heuchera 'Lime Marmalade' :
and this is another Heuchera 'Alabama Sunrise':
There are lots of purple Heucheras, easy to obtain. Hope that gives you a couple of suggestions.