Always use sources. This cannot be stressed enough. Mention your sources in the footnotes, so that it will empower the next generation to have a point of reference for future genealogical research. Be objective.

Every family has its high period and low periods, ancestors that make you proud but also ancestors that don't make you proud. It is very important with sources to use them correct. Do place them in the correct stratification.

Your family could be wealthy in 17th century, but poor in the 19th century or vice versa. Do then also try to explain the source of wealth or poverty. When doing this use the spirit of that age as a background.

Personal memoirs of family members can be useful for "tasting" the sphere of those times. Using the guidelines above will guarantee you enjoy doing research and learning from your ancestors.