The damn drinks are way too expensive. I bought an espresso machine from goodwill a number of years ago, but could never quite get the flavor right. I finally figured out how to do it, and thought I would share. It's not all that difficult. I get a month's worth of drinks for about $15.
First of all, you need an espresso machine (duh!) I got a really nice one that retails for more then $200 at goodwill for $12. Admittedly, you don't see these there very often, but I do see smaller cheaper ones there on a regular basis. Just be sure that it has a milk steaming wand.
Next, you need the coffee. I go to the grocery store and buy whatever whole bean coffee they have that is cheap, as long as it is a medium roast coffee. I don't trust myself to get it ground right at home, so I use the grinder in the store set to "espresso". If you want actual Starbucks coffee, grocery stores sell that too - look for "house roast".
You also need syrup. I get mine at grocery outlet for about $2 a bottle, and I've heard that it is really cheap at a place called Cash & Carry, but I don't know if they are nationwide or not.
Of course, there is the obvious, milk and utensils. I got an aluminum glass from goodwill to steam my milk in. I don't trust ceramic or glass for this part - I'm worried about it breaking. Be sure that you get something with a handle, or have a good potholder to protect your hand - it can get really hot! The thermometer really isn't necessary, just listen to what the milk sounds like next time you go into a café. I can tell whether or not the milk is a good temp by listening to its "scream"
Now that you have everything you need, you need to make the coffee. place your grounds into the little cup that attaches to the machine. you need to press them down, I used to use my fingers until I discovered that a glass spice bottle is about the right size and shape, so now I use that. It takes a little bit of practice to figure out how much to press down, but don't worry, it's still good even if you don't get that part quite right. Attach it to the machine, put in your water, but don't turn it on yet. Get your milk ready in whatever container you want to steam it in. Now, turn on your machine. if yours is the type that the water that feeds the steam wand is the same as the water that you make the coffee with, turn the nozzle on and place it in the milk once about half the coffee is in your cup.
Keep the nozzle in the milk until it sounds right (or until 160 degrees if you use a thermometer) and then slowly pull it up till it is near the surface to make the foam. Once the milk is hot and foamy, close the nozzle and let the coffee finish brewing. IMPORTANT: do NOT remove the thing holding the grounds until the machine is completely cool (I generally open the steam wand nozzle all the way while it is cooling). If it is not, there is still pressure from the steam in there - I learned this the hard way and once I loosened it, it shot off the machine, into my cup, and I wound up with coffee and broken ceramic flung halfway across my house.
If you are going to put in syrup, do so now, and then pour in the milk, using a spoon to hold back the foam until the very end, then scoop the foam out on top of your coffee.
I've found a few links that were helpful in figuring out how to make different drinks.
This one gives amounts of ingredients.
and this one tells which flavors are used to make which drinks.
The first link says "mocha powder" but I've discovered that Hershey's syrup works just as well.