Step 1 is the easiest and cheapest technical step. This is just the beginning of the process but it does need to be done correctly. Texas has very specific rules when it comes to filing for divorce or family law matters so be sure to hire an experienced attorney if you’d like some guidance. So what county do you file a lawsuit in?
For a Texas divorce, you may file in a court in the county where you have been residing for the past three months, as long as you have been a resident of Texas for the prior six months. Sometimes a couple has been living separately and live in 2 different counties. In this case, it is possible that a divorce action could be filed in either county. In this case, it becomes a race. The party that files first (in the proper court of their residence), establishes the court for the action.
Family law cases not involving divorce (such as a child custody case between unmarried parents) have different rules for a court having power over the parties. They usually revolve around where the child has lived most recently (for the past 6 consecutive months). I have handled cases where there were 2 or more children that were divided between two households (i.e. a child lived with each parent) , which can cause there to be quite a bit of confusion over the proper county to file the suit. Again, the party that files first would have an advantage in this respect.
On the other hand, modifications of existing family law orders usually have to be initially filed in the county where the existing order is. Sometimes the case can be moved after the initial filing to the new county where the kids reside, but this will require a specific motion and/or hearing. This can be a major tactical advantage or disadvantage for you in your case so it is important to consult an attorney to guide you through the process.