Three notes about skills: 

• If you’re just finishing a degree program, you may think of your knowledge organized around topics (e.g., courses) or technical skills (e.g., GIS, statistical analysis, cartography). 
• Remember that employers are looking to solve particular problems, so they’re also interested in how you’ve applied your knowledge to solve problems (research problems, work problems, clarifying tasks) and in your overall attributes.
• Your portfolio provides an opportunity to give and illustrate examples of your problem-solving ability.

• Don’t overlook more general skills, which probably aren’t reflected in the titles of courses you took, but which you can point out and document: 
• project management
• people management
• written, oral, and graphic communication
• teaching, training, or explaining to others
• library and online research
• assessing the quality of information sources
• team organization
• working amidst ambiguity

• Don’t overlook basic characteristics, which you should strive to assess and improve:  creativity, punctuality, trustworthiness.  These are all capabilities that you’ve probably developed during your academic study and school-time employment:  what can you show to illustrate these capabilities?