What should I be doing to prepare for a modification?

The answer depends a little bit on your circumstances, but generally speaking, you should be keeping a timeline of events that have occurred and any evidence you might have to support it. If for instance, the other parent sends you a nasty text message, you should have a place where you write down the date and what was said, and then print out the text message and save it with the other evidence you have.  

If the Court ordered you to do certain things, such as attend counseling or complete a parenting class, make sure you do that and keep a record of it. The items the Court requires of you are not only mandatory, but i the judge is signaling to you what changes the judge wants to see before increasing your access to the child. You may not agree with the judge, but we recommend you follow what the judge has required of you to increase your chances for a better result next time around.  

For spousal maintenance and child support, keeping your financial records so that you are ready to go on discovery and disclosure is important and can save you a lot of time and money when you are ready to modify.