I was working on an old deck list from SaffronOlive back from 2018, UW Monks. I loved the deck, but the meta has changed A LOT since then. At first I stuck with the UW theme and had tokens with Monastery Mentor as one of the big reasons to run the deck. It also had Smugglers Copter as a repeatable card draw and decent flying chip-in damage. You can check out the old list here: https://www.mtggoldfish.com/articles/budget-magic-94-49-tix-uw-monks-modern
At first I just upgraded some of the spells;
Cut Vapor Snag, Mana Leak, Shared Discovery, and some lands
Added Founding the Third Path, 2nd Legion's Landing, Counterspell and changed some numbers on the lands.
The deck was okay, but the tokens never stuck around long enough to change the game. Only sometimes did the prowess tokens even matter outside of crewing the copter.
I then realized that I also had a Jeskai Control deck that I was slowly building up (Needed 3 drop Teferi, Archmage's Charms, Flusterstorm, Force of Negation). I had a decent shell, and just decided to add the Myth Realized, Considers, Unholy Heats, and Pyrite Spellbombs and cut some elements that wouldn't fit from the old jeskai control list (Spreading Sea, Supreme Verdict, Shark Typhoon, and Celestial Colonnade).
I am still testing numbers and such, as well as trying out other cards in this build. Cards such as Founding the Third Path, Opt, Fire//Ice, ect.
EDIT: I realized after posting I never talked about the sideboard. It's pretty self explanatory, but I will just give a quick summary. (Always subject to change during testing, and will edit this part as I go).
2x Dovin's Veto and 2x Mystical Dispute for more spell heavy/control decks
3x Paths for decks with hard to kill creatures
2x Wear//Tear for hard to deal with enchantments and artifacts
2x Damping Sphere for Storm and Tron
2x Rest in Peace for graveyard focused decks. I know I could use Tormod's Crypt or Relic instead so I don't screw myself over, but I dislike having a one time use artifact and popping it too early. Siding in RIPs usually means taking one Snapcaster out + something that isn't working for the matchup.
2x Stony Silence for troublesome artifacts like Baubles or equipment like swords or Kaldara Complete.