The real Feature Structures
Most linguists use the term Feature Structure and mean Attribute-Value-Matrices (AVMs). AVMs are just a different way to express feature sructures. Real feature structures are labelled very similar to trees. Feature structures are models of linguistic entities, whereas AVMs are feature structure descriptions and only describe the linguistic entity. In a feature structure every attribute that is possible must be present and have a maximally specific value. They are always complete. AVMs, on the other hand, can be used just to highlight certain aspects and need not be complete. They are typically used to group linguistic entities.
Here is an example of a feature structure for the word Kim (reproduced with kind permission from M. Sailer):
Exercise: Draw a feature for the verb walked.
Here you can see the solution.
See the chapter on Unification if it will work!