This follows along the lines of having your workout gear ready and in the car the night before.
On Saturday or Sunday, many of us prepare our meals for the week (Meal Prep Madness!).
Build out a similar routine for preparing your gym clothes. If you have enough shorts and shirts, layout outfits for each day you plan on training. Since many of us do laundry on the weekends, you should have plenty of clean gear.
This serves two functions. First, one aspect of getting ready for the gym is already done in advance. One less hurdle to overcome.
Second, you start mentally seeing yourself at the gym wearing the clothes you picked out. The more you see yourself doing it, the higher the likelihood of you actually doing it!