A quick and easy way to get students speaking is to have them describe a picture or photo, but this can a get a little old after a few times. There are many paired and group activities that students can do with an image beyond a simple description.
–One student orally describes a picture to a second student who then draws a copy of it.
–One student orally describes a picture to another student who then is given a choice of pictures and must choose the one described.
You will need to find pictures (easily done on the Internet) that represent the vocabulary that your students know. A lack of vocabulary is a common reason for breakdown with these activities. I suggest reviewing language “chunks” that will be necessary for communication before students begin; i.e. “there is/are”, prepositions, colors, etc.
Here is a great document with 50 ideas for using an image to get students speaking in the target language:
Using Visual Material in the Foreign Language Classroom (Compiled by Harry Grover Tuttle)