be chatty!!
join in on the forums here, firstly - if you regularly provide interesting conversation both in the fun threads (bitching, watercooler, others that come and go) and the more technical threads, people come to be aware of you, and if youre friendly here people will be friendly with you.
on tapas itself, this also goes - if you like someones comic, comment!! a lot!! send them DMs (occassionally, dont overdo it) about things youve noticed they might want to change (be nice though!! ive developed a good rapport with other creators by DMing them now and then w a comment abt their icon or their lettering that goes along the lines of 'hey i really love your comic, especially x element and y element, and i wanted to let you know that (z minor issue.) i think if you just tweaked that a little itd take your comic up from a high 9 to a solid 10, and i really wanna see that happen. keep up the great work!! ill be here cheering you on.')
the important thing with that, though, is be sincere. and patient. i dont think its a good idea to directly approach someone - particularly bigger creators - with just 'can we be friends?' because often that will make people suspicious. youre better off being very open and generous with your praise of comics you love, and developing alliances with creators on your own level on the forums and by sharing the occasional heads up on the DMs.
theres also quite a few discord servers going around, and they can be brilliant. i got in on one back when it was an appear.in hangout, and not only was it really good for my work ethic (i was always on there while i drew, and it kept me on task so well) but i also now have a pretty tight circle of friends, and we swap advice and help eachother in many different ways in the comic-making process. so yeah, if you can handle groupchats, id recommend it.