A tape measure is the most basic tool needed for molding projects. You will need it to measure the distances on walls where you plan to install molding. The most common length of tape measure sold is 25 feet. You can purchase one that is longer in order to measure long walls more accurately than stopping mid-measure using a shorter tape measure.
An adjustable protractor will help you measure the angles of walls. Many rooms have inside angles where two corners meet. In some molding projects--such as kitchen cabinets--you may need to measure outside angles. While it is easy to believe that all angles look like they are a perfect 90 degrees, an adjustable protractor will help you ensure that this is a correct assessment. You simply need to place the hinge on the corner and move either side of the protractor to be flush with walls.
A miter box and saw is often the easiest way to cut molding. After you measure the molding, you simply place the molding into the miter box. The box will usually have three slots: right angle, middle and left angle. The angles are at 45 degrees and the middle at 90 degrees. The accompanying miter saw typically has a smaller teeth set for finer cuts, often a requirement for molding.
Coping saws help you create special cuts for molding. They have thin blades that bend easily so you can trace the design of molding for joining pieces together at corners. The teeth set on coping saws are pretty fine; this creates extremely smooth cuts, although it often takes longer to actually cut the molding.