While much of the emphasis revolves around warm-up before running a nice cool down program is worth its while. After your next long run, take an extra 30 minutes to consider the following routine: 

• Cool Down Walk- to lower your heart rate and drop body temp closer to normal
• Stretch while your warm and limber to increase flexibility
• Ice down for 15 minutes to reduce inflammation especially to overuse areas of the knees and feet
• Take in some replacement carbs and protein....maybe a nice glass of carnation instant breakfast (for a economical carb/protein combo)
• Take an elevated load off by elevating those tired legs and feet just above heart level to alleviate pooling