If you find it difficult to pick subtle shades of a color from the color palette, create two objects with no outline with one object being a darker shade and the other the lightest. Blend these two objects together with the Blend tool and adjust the number of steps to give you the appropriate number of shades. Use Arrange>Break Apart to convert them into regular objects instead of a Blend group. Now simply drag all the objects to the Document Palette. This will add the shade of color to the Document Palette so they will always be available with the drawing.

Tip provided by Roger Wambolt, CorelDRAW team.