U/W Clue Mill (Standard)

Early game creatures to be used as chunk block/apply a little pressure to the board and allow early game card draw with clues.
Turn 3 enchantments to begin milling on each draw or when you sac a clue.
Turn 5 Tamiyo's Journal to begin the major milling. As well as draw specific cards from your own deck (really useful for control)
Stall with skyline's Cascade/Engulf the shore. (Engulf the shore only bounces creatures. Due to the fact this deck only runs low cost creatures it's very easy to replenish the board after it's use.)
Clash of wills for either early or late game counter spells.
Plains walkers with great benefits from emblems.
Running only 2 Day's Undoing because by the time you draw 1 it will be about the time to use it to replenish your own deck which should be it's main use.
Evolving Wilds use is to pretty much only pull out your plains if you do not get them during your draw.
Port town and Prairie Stream were included to assist in fixing the low amount plains included in the deck.

Sideboard:
I was really unsure about the Sideboard for this Standard route. However it allows for quite a few variations. I included what I have and the reason why/how it runs in this deck.

1) Declaration in stone if opponent is running really aggro low cast same name creatures which will exile and not get rerun back into opponents library after casting Day's Undoing.
2) Ojutai's Command (since all your creatures CMC is 2 or less you could pull any of them. Gain 4 life if against aggro. Draw a card (shouldn't need it). Another Counter Spell.
3) Startled Awake for another creature (after using the card for extra mill which can rebound with Narset Transedent).
4) Trail of Evidence to supplement when changing out Main Decked cards with Sideboard.
5) Void Shatter another counter any spell with exile. Especially useful if playing against another control/blue based deck. Once again since opponent's card is exiled it will not go back into the library when playing Day's Undoing.