Do you ever use New Game Plus?

I find that whenever I start a second playthrough of a game, I tend to just pick the new game option. Especially if the first playthrough was years ago, a new game + would make me feel like i'm playing with "someone else's inventory". Like you started up a previously existing game from a rental.

There are a few exceptions, like Chrono Trigger, where starting up a new game after the first playthrough can help you see different endings pretty early on in the game and give you an alternate playthrough.

Not usually, mostly just because I almost never replay games. I play them mainly for the story, so it's not worth it for me to sit through hours of stuff I've already seen just for some minor additional content then can only be unlocked in your second play through. I've learned to just start off with a walkthrough for the sidequests, so I rarely miss stuff in that department anymore. The only games I usually replay are visual novels, both because they have multiple routes and and endings so I'm seeing a ton of new content each playthrough, and because they feature a skip button so I can pass over content I've already seen.

It depends on the game. Generally, short games with NG+ will likely see me do it, but if I know the game is going to be an 80 hour behemoth and I haven't played it in years, I might just start over.

NG+ only really works for me if there is a reason to replay it. Just playing the game with a semi-god mode play isn't enough for me to go through it. I prefer games like Chrono series with multiple endings, or Dark Souls with the increased difficulty to get me coming back.

All the time! Especially Persona 3-5, it's hard to get everything on a fresh game without a guide. It's nearly impossible in the original Persona 3 without a day-by-day guide 'cause all the girls are your girlfriend and you can't make them jealous of eachother :|

Sure, I used it on Chrono Trigger all the time, but Chrono Trigger was perfectly designed for New Game + and most games are just copying the idea without being well designed for it. The multiple endings and the ability to fight the final boss at nearly any point on New Game + is part of what separates CT from some other games that just let you carry some stuff over into a new game. Also, the fact that CT is a fairly short game made quicker by NG+ helps. I would often just cycle through the game over and over increasing my stats on NG+. Nowadays a lot of games have bloated length and I don't really feel like playing through them multiple times. Even if NG+ makes it quicker it might not be worth it. Add to that the problem that NG+ can make a game feel boring and I might prefer replaying a regular new game over NG+. For some reason, this was never a huge problem to me with CT, but again, I think the game is just perfectly designed for it. Most games it will completely kill the fun and if you really have to fight a ton of battles anyway (which you generally don't in CT) it can become a chore. I've done it for Persona 5 too. I've got to say though, even there it kills some of the enjoyment. At least the game gives you some reason, but aside from optional bosses, Persona 5 was kind of too easy the first time through. Playing on NG+ with end game equipment and the ability to buy high level personas from my compendium (which I try to keep to a min to increase my enjoyment), just destroys even the small semblance of challenge. Then I went and cheap killed the reaper before the sixth dungeon and it won't even let me fight battles anymore if I sneak attack. To make matters worse, it still didn't really get me strong enough to take on the other optional boss.....

I do if I love the games enough :) Especially when new stuff and endings are included !