Choose a fully cooked ham that fits in your slow cooker
Trim the ham if needed so the lid closes properly
Place the ham cut-side down in the slow cooker
Add 1/2 to 1 cup of liquid such as water, broth, apple juice, or pineapple juice
Cover and cook on low for 4 to 6 hours
Heat until the internal temperature reaches 140°F
Baste with the juices once or twice during cooking if desired
Optional: brush with glaze during the last 30 to 60 minutes
Optional: make a glaze with brown sugar, honey, mustard, or maple syrup
Let the ham rest for 10 to 15 minutes before slicing
Slice and serve with the cooking juices if desired