Get PC Potion

Lead HA on Bug Catcher 1's Second Caterpie (HAx2, tackle)

Heal if 20- for Lass (not unlikely to need to heal in fight)
Lass: HAx4

BC3:
Caterpie: PS turn 1, Flex Turn 2
Metapod: HA, PS, HA (sometimes PS)

Kill an encounter (not L3 Puff)

Before Rocket
Toss remaining balls (and antidote)
Rare Candy
Teach Water Gun in slot 2
Moon Stone
Teach Mega Punch in slot 1
(there is a strat that teaches water gun later in order to save muscle memory (but is slower))
Rocket: MPx2 (Zubat is a range)

Nerd:
Grimer: MP, Tackle if you have it still, otherwise Flex
Always MP Koffing turn 1 (Crit is a range to kill at 17)

Bridge:
HA both Zubats

If miss into String shot on Caterpie, use HA on it and Weedle

Candy before Rocket (teach water gun in slot 4 if you have not already)

Misty:
If miss into Leer on NidoranM, use Horn Attack on it. Mega Punch NidoranF if Leer as well.

Teach thrash over either tackle or Poison Sting (whichever you still have) when you hit 23

HA Machop at 13-24 HP (64% range)

Thrash Lass

Skip Ether

Still do early dig rocket

Do Vermillion Mart AFTER boat (does matter)
3 repels 5 para heals

Cut Menu: 
Swap 1 with repels
Teach Cut
Teach BB over Water Gun
Teach Dig

Bike Menu, swap 3 with bike, teach TB

Get Max Ether

Remember bike is in slot 2 for underground

Early Drill guide:
1-7 Early Drill, Potion turn 1 then X Acc
8 Early Drill, X Acc on Growlithe
9-15 Don't early drill
16 Early Drill, X Acc on Growlithe
17+ Early Drill, X Acc on Pidgeotto

Early drill is fantastic in races due to the general fact that 3 supers barely matters vs. 4. It saves a menu and lets you X Acc+ Drill Arbok.

Buy:
TM07
10 Super Repels
4 Super Potions (3 on Early Drill)
2 Revives

1 Poke Doll

Soda Pop (trade for Rock Slide)
Fresh Water

12 X Accs (13 on Early Drill)
6 X specs (5 on Early Drill)
3 X Speeds

Fly Menu:
Early Drill

Swap 2 With TM07
Teach TM48 (Down 4) over thrash
Teach Horn Drill over punch
Swap 2 With X Accuracy
Teach Fly

No Early Drill

Swap 2 With TM07
Teach TM48 over Mega Punch
Swap 3 With X Accuracy
Teach Fly

Ghost menu: Swap 3 for super repels, use Poke Doll (3 Down)

Thrash on tower rattata instead of raticate if non early drill (you have greater attack due to lass)

Silph:
Arbok: Thrash if no early drill

Silph Rival:
X Acc, Swap 8 for X Specials, X Speed (Remember to Rock Slide Growlithe if Early Drill)

Max Ether at some point before you start horn drilling

Snorlax Menu: Super Repel, Swap 4 for Rare Candy, Poke Flute

Get Rare Candy and PP Up

Fuchsia Menu: Super Repel, Swap 8 for X Speed, Teach EQ over Thrash/Rock Slide

Post Koga Menu: Use 3 candies (slot 4) then bike

Surf Menu: Super Repel, swap 4 for PP Up, teach Surf to Squirtle

Blizzard menu:
Teach Strength to Squirtle
Teach Blizzard over Bubblebeam
Super Repel
PP Up Drill

Pickup Candy

Viridian Rival:
X Acc, X Speed, Blizzard (x2 (Or TB if Rhydon took 3 Blizzards)), Blizzard, TB, EQ, EQ, HD

Note: 
For Elite 4, Elixers are slot 3 and X Specials are slot 4. This means that you can double input to elixers on Bruno and Lance menus, and you need to either triple input or fast scroll to X Specials on Agatha. (After Lance menu X Specials go to slot 3)

Dont forget agatha candy

You can drill champ x6 (assuming no sky attack turn 1 of course)