1. Flirt with other men
That's right... if you wanna make him jealous then a little flirty banter here and there is OK! He needs to be kept on his toes so he knows your worth. When you're out and the waiter or bar tender are nice to you, there is no harm in starting up an innocent conversation.
2. Have male friends
If you have male friends that text you or call you once in a while, this is sufficient to make a man jealous. The fact that some other man has your attention and potential trust will make a man go crazy! It will especially make him jealous if this male friend makes you laugh.
3. Going out with the girls
Girls night out is the territory of "what is she doing and what other guy is looking at her/talking to her". So in order to keep his imagination going, make sure to look hot and have fun that evening!