Bring the right tools for the job. Do not be impatient with your work. When using a compass, there must be some well-defined point for the center point, such as the intersection of two lines. Center the compass precisely on that intersection. Depending on the complexity of the construction, small errors may be greatly magnified.
All points used in construction are intersection points.
They can be the intersection of two lines, two arcs, or a line and an arc. Two intersections are shown in the figure below. Two lines can have no more than one point of intersection, but our drawings of lines have thickness, so the drawn images intersect over a small region. In the figure on the left, that region is stretched out, so it is difficult to pinpoint the location of the point of intersection. In the figure on the right, we can get a more precise fix on the intersection.