1. search the internet for
1.1. texts
1.2. photos
1.3. videos
2. describe your instrument
2.1. name
2.1.1. This is a ...
2.1.2. My instrument is a ...
2.2. type of instrument
2.2.1. It is a ... instrument.
2.2.1.1. string
2.2.1.2. woodwind
2.2.1.3. brass
2.2.1.4. keyboard
2.2.1.5. percussion
2.3. material
2.3.1. It is made of ...
2.3.1.1. wood.
2.3.1.2. metal / brass.
2.3.1.3. plastic.
2.4. sound production
2.4.1. The sound is produced by ...
2.4.1.1. moving the bow over the string.
2.4.1.2. plucking the strings with the (right) hand(s).
2.4.1.3. blowing into the mouthpiece and ...
2.4.1.3.1. opening or closing the tone holes.
2.4.1.3.2. pressing the valves.
2.4.1.3.3. moving the slide.
2.4.1.4. pressing the keys.
2.4.1.5. beating it with a stick / the hand(s).
2.5. history
2.5.1. The ... is (not) a very old instrument.
2.5.2. It was invented in ... (by ...).
2.5.3. It has been played for (about) ... years.
2.6. musical style
2.6.1. It can be used in ... music.
2.6.1.1. Classical
2.6.1.2. Folk
2.6.1.3. Pop
3. say why you like this instrument
3.1. I like the ... because ...
3.1.1. it's very loud.
3.1.2. it has a beautiful sound.
3.1.3. it is easy / hard to play.
3.1.4. I can ...
3.1.4.1. play it ...
3.1.4.1.1. alone.
3.1.4.1.2. together with others.
3.1.4.2. use it in a band.
3.1.4.3. sing while I'm playing.
4. mention the sources
4.1. internet
4.2. books
4.3. magazines
5. say how long you have been playing it
5.1. I've been playing my instrument
5.1.1. for ... years now.
5.1.2. since ...