Basic Deck Stats
Ramp: 10-12
Card Draw: 10
Single Target Removal: 10-12
Board Wipes: 3-4
Lands: 35-38

Standalone (cards that are effective by themselves/with commander): 25
Enhancers (cards that amplify or are amplified by standalones or commander): 10-12
Enablers (covers a weakness or fills a gap in your strategy): 7-8

Cards on your theme: 30(ish)

1-2: 14-15 Cards
3: 12-16 Cards
4: 8-10 Cards
5-6: 6-9
7+: 3-5

Find overlap
Consider...
Overlaps (cards that count in multiple categories)
Partials (cards that count as 'half' in a given category. E.g. scry 3 as half a card draw card)

Quadrant Theroy:
1) Developing stage
2) When I'm at parity
3) When I'm behind in the game
4) When I'm Ahead in the game