Here on italki, too, there seems to be language learners who are quite active just for a very short time and soon never come back. Some of them may be still learning by themselves but the others may have gotten tired of learning in short. I think the latter case is very possible; like a very short try or hobby. I guess you are a serious learner. So, you may want to find partners who are, without a doubt, like you. Their long term use here, for a couple of months for example, may be helpful to see if they are serious learners.

Don't unreliable people make you lose faith on this world! :)

Idk about tips, but you can obviously meet people here and also there is an app for Android and IOS users called HelloTalk which is great for language exchange! :)

Ganbatte! 

I think it's hard to find long-lasting laguage partners because we sometimes get too busy dealing with others things. Plus, we don't necessarily want to share the same topics. But as for your writing skills, I'm quite sure that you can find somebody talk to in Japanese temporarily by posting something as a discussion here. You can talk about anything: food, spors, TV shows, books, the recent news etc.