Half-toy, half-pretending-to-be-serious medium format camera, the Holga is tricky to get right, but when you do, your heart will leap and make the wait - between shooting and getting the film back - that much sweeter.
Film is magic. Nothing proves that more than a cheap, plastic Holga.
My tips? Load it up and go, but the following are things I've lived and learned along the way.
Helpful: This incredibly useful website will be your friend, especially the Troubleshooting section. Bookmark it immediately.
Read the manual. I must admit to being very bad at this usually, but the Holga manual only takes about 15 minutes to read from back to front and back again, even if you're a slow reader. It's about as basic as a camera gets, the Holga, but it makes dreamy photos because of its simplicity. Go with it.
Relinquish control. At least for a while. You can learn to wrestle it back later on, but start out expecting little and you'll have much more fun, I promise.
Throw away the lens cap. You will forget, you see - voice of experience, here - to take it off and waste both film and money. You only get 12 negatives per roll of 120 film. Wastage is bad.
Tape it up. Holga's are well known for leaking light into the film. Sometimes this will work in your favour, but mostly you'll just want to cry. Grab a roll of gaffer/electrical tape and seal that camera back tightly, baby.
A pain, but worth the effort. Really.
Use the 'N' setting for a while. It's tempting to play with the 'B' (bulb) setting, but stick with 'N' (normal) 'cos otherwise everything you shoot will be a blur. Again, you'll cry and again, wastage is b-a-d.
Oh, and shoot in strong, natural light.
Take it with you everywhere. Weighing it at a tiny 250 grams, a Holga weighs less than the average paperback...so don't leave the house without it. You never know, you see, when the light - and the moment - will be just right.