Finding the Fun in Preseason
This is just wall of text about player behavior around preseason and how I think you should best spend this time (for enjoyment purposes, because that's what games are for). With all the complaints and threats of quitting that go around this time of year, I just thought I'd share what I do.
The only "credentials" I have are playing since Cassi patch (woooo), so I've seen a lot of sweeping changes come through here. Let's dive right in, I guess!
So there's a lot of complaints, ultimatums, and cries to Riot to nerf this, change this, reinstate this etc, etc. And these things are perfectly normal around preseason or any big changes that shake things up, but I'm still confused as to why people view the game like this. You wouldn't consider yourself equipped to talk about nerfs or buffs to a character with a very small number of games on them, so why talk about Preseason like it's the end of the world when there's no possible way anyone has put in enough time to really fully understand the changes? I have a much better idea for what I do during Preseason that both improves my understanding of the new game systems and is fun, and I think that if you're having a hard time enjoying Preseason or understanding what's going on, it may help you!
So first things first, I look at my roster of champions and pick one. I build a runepage and mastery page for that character (fresh and new, like I've never played them before, no matter who it is). Then I play a couple games as them - try out the new items or whatever may be relevant, and keep track of what I really enjoy (Thunderlord's Decree Karma is so spicy =D). Keep doing that with champions until you find your "new pool". Every season there are going to be different champs that YOU enjoy, or that YOU feel are strong, and this perception is important - you generally play better if you feel confident that your champion is capable of contributing to your team/lane phase/what have you. I generally do this until I have a pool of 4-6 champions in a couple different roles that I feel really comfortable with under the new system (so I know my item paths taking new items into account, have played a few matchups and have an idea of how to win and what makes me lose, etc).
Then I spam the crap out of these champs, focusing on champs that are enjoyable to play and focusing on my own personal gameplay improvement.
This style of gameplay has helped give me insight into how I really feel about certain changes - like, I hate playing against Tryndamere with new masteries but I feel like Yasuo still suffers from a lot of the problems he did before (lack of synergy with some team comps, reliance on his team to set him up for fights most of the time, and the long CD on Windwall). This helps me gain a larger understanding of how I, personally, feel about the changes. Focusing on your own gameplay and how the changes effect you personally is a good way to get a healthier understanding of them - trying to talk about things in a vacuum is difficult because while certain things may not look that impressive (lots of people were saying Thunderlord's Decree was bad when it was on PBE) but may actually be awesome in practice (Thunderlord's Decree is a free Luden's Echo proc that has better scaling at all points and better base damage past level 10).
tl;dr: When judging Preseason changes, look at how they effect your gameplay personally before you try to talk about them, and try lots of new things to aid your understanding of how changes work, instead of just reading patch notes and claiming the game is worthless now.