How to stay motivated at the gym?

Choose a gym which is closer to your locality first of all. That will kill your laziness to some extent at least. The key is to find an instructor that you click with and introduce yourself. Once you know the teacher, you will be excited to go to the class so that you can say hi. It will also make you feel accountable to someone if you know he or she will notice if you are there. befriend someone at the jym like a jym buddy so that you are look forward to meet your new friend(s) in the jym. They can be your motivation. Write down every single day what you did as far as exercise goes. The thought of writing "nothing" may motivate you to just get it done. Go buy new pair of shoes or good track suit or jym clothes especially for the workout. The clothes will act as a motivation for sure.

Ask your gym instructor to make variations in the exercises, speed up some of them, increase or lower the timings accordingly so that you are not bored of doing the same thing again and again. Change is good at times and necessary too. Take motivation from those who are fat, extremely fat and target a goal and the weight you want to reach so that you are always on your toes. It is a good way of finding positive in negative too.

Hey Surabhi,
Along with the tips given by Eva and Manasi, Prefer doing your workout in group or have some friends, group exercises keep boredom away and provide a common forum for the discussion of day to day problems, competitiveness among the individuals which is in itself a motivating factor, listen to your Favorite music to boost you at gym etc.