Fields with a * are mandatory.
To maximise your results it is best not to use a middle name. You can also try using variations of the first and second names as the records are copied from handwriting that was often hard to read.
Try searching without a place of birth to start with as place names may have changed over time. If you find you have a lot of results you can enter one later to refine your search.
When searching for women try both their married and maiden names.
If you want to search for people born a few years either side of your stated date, use the give or take box.