theyre cute, and i like the opportunity to reply w compliments abt the comic. it makes me feel like the creator is more aware of me as a fan, and im more aware of the creator behind the comic.
images with the text is commonplace and id recommend it. most people have a single thank you image they send around, usually consisting of one or two major characters from the waist up.
uhhh commission giveaways? to celebrate the 2 days a year college students arent drowning in work. you could make stickers on smth like redbubble (preferably somewhere w discount code options) and give them to like, your 100th subscriber or in another giveaway. if they have comics, you could check them out and engage with them, i guess.
id say the best thing is to engage with your subscribers. give them reasons to comment, and reply to their comics. you can get really long, really fun threads going sometimes.
course not. your comic exists, thats plenty time enough to send thank yous to new subscribers. i started doing it maybe half a chapter into my comic, and didnt give one out to all the subs before then because the delay felt weird, but everyone after got one.