Ideas for iterating good recipes

I'm on track to really nail recipes of 2 of my favorite beers. Version 1.0 of both my ESB and Porter have been brewed and turned out well, and now I'm all ready to adjust a few things to see how they differ next time. For the ESB I'm thinking of changing hop comibnations, and for the Porter I'm looking at the grain bill moreso. Your thoughts on recipe critiques or suggestions for changes to the next brew would be appreciated.

ESB:

OG: 1.050
FG: 1.013
IBU: 40

Fermentables
Ingredient Amount % MCU When
UK Pale Ale Malt 10.00 lb 93.0 % 5.0 In Mash/Steeped
UK Medium Crystal 0.50 lb 4.7 % 5.0 In Mash/Steeped
UK Dark Crystal 0.25 lb 2.3 % 3.2 In Mash/Steeped

Hops
Variety Alpha Amount IBU When
UK Golding 7.2 % 1.50 oz 35.5 60 Min From End
UK Golding 7.2 % 0.50 oz 4.3 10 Min From End

Yeast
DCL S-04-SafAle

Mashed at 152 and fermented at 68

Porter:

OG: 1.061
FG 1.014
IBU: 33

Fermentables
Ingredient Amount % MCU When
UK Pale Ale Malt 8.00 lb 59.3 % 2.3 In Mash/Steeped
German Smoked Malt 3.00 lb 22.2 % 1.4 In Mash/Steeped
US Caramel 60L Malt 0.75 lb 5.6 % 8.2 In Mash/Steeped
UK Chocolate Malt 0.50 lb 3.7 % 40.9 In Mash/Steeped
US Black Malt 0.25 lb 1.9 % 22.7 In Mash/Steeped

Hops
Variety Alpha Amount IBU When
US Nugget 11.2 % 0.75 oz 27.6 60 Min From End
US Liberty 3.7 % 1.25 oz 7.5 15 Min From End

Yeast
US-05

Mashed at 154 and fermented at 68.

Thanks for sharing your ideas. I built both of these recipes from all that I've read here, you guys rock.

You might want to try lightly dry-hopping your ESB. Maybe 15-20g. I like using Saaz for that, but Goldings would be fine.