I do the same, but finding the S8+ is a mite much for most of my shirt pockets and can easily slip out. I can't figure how anybody can use their front pants pocket though, I'd have to wear cargo pants to hold the stuff I keep in that pocket. The phone does fit there, however I find getting it out in a hurry to be very iffy.
I carry mine in a Spigen case, in my back pocket most of the time. I've always carried my phone in my back pocket and never had a problem. When I sit down, I pull it out and set it on the table or whatever, or in my lap or between my legs.
Been doing it for years. Sad to say but I'm too attached to my phone to leave it somewhere or let it leave my sight.Hmm, don't like this. Forget and you have a cracked phone. Also good chance of leaving the phone laying somewhere. Glad it works for you though.
Had a Note 5 that I loved but just was a bit too bulky to slip into my front pocket of my shorts or jeans. Upgraded to the S7 edge and it fits perfect with just a Spigen slim case on it. Swung by Best buy and nobody had an S8+ that didn't have an alarm on it so I could try out the "Pocket-ability" of it is compared to the S8 and S7 edge.