-When following the fame career path, talk about yourself over and over. When you are at 100 in daily liking the person you are trying to be friends with, say goodbye and wait until the next day. Then call them up and talk, but do not invite them over. If you just talk to them for a bit (it does not matter if they yell at you or engage in conversation), they should automatically become your friend. You can then invite them over and engage in normal conversations and do things together that you can do with others, even though you are at a lower level than they are.
-If you have The Sims Makin' Magic and Superstar, you can easily get more famous friends by speakingg to them then casting either the Smiley Face spell or any other one that improves friendships. You will get fined, but it is usually around 20 Simoleons only if the magic person catches you. Make sure that you have enough Mechanical and Logical points so that the spell does not backfire.
-The The Sims Makin' Magic is required for this. Have the following ingredients: Honey, Toad Sweat, Garlic. Add the ingredients in the Spellmaker. Charge your wand and you will have the Smiley Face spell. Then, go outside and get the paper (not the newspaper). Select "Find An Agent". Certain stages of your fame career will require a number of famous friends for you to move on to the next stage. Go to Studio Town and meet some new friends. Most of them will be kind of famous. Next, go home and invite them over. Once they are over at your house, cast the Smiley Face spell and your Famous Friend meter will go up.