You can uphold teachers' work through magnanimous gifts, or show your appreciation with smart gifts, similar to interesting shirts to cheer them up. So feel free to chuckle with your instructors today. You'll be happy you did.
With regards to modifying a shirt, your choices are endless. Assuming you have a little financial plan, be encouraged; there are a lot of reasonable ways of allowing your imagination to roam free and make some banging shirts.