I've been using Option 3 Rhaelys mentioned, and I've been a huge fan.
Option 3
Level 30
Strength: 21
Agility: 15
Hit points: 70
Converted: 2
Ironflesh: 7
Power Strike: 7
Shield: 5
Athletics: 5
Weapon Master: 5
One Handed: 148
Power Strike 7 seemed way better than 6 when I leveled it... I notice a lot less glance on heavy armor with my Italian sword. The 5 shield and athletics are just fine, and keeping my agility at 15 has been totally worth having all those extra points in ironflesh.
I don't see myself going any different build as a 1h shielder tbh.
This is a pretty solid build (if you ever tried played without IF, I suppose you love your 7 points in it), but athletics can make a tremendous difference too.
I think if a newcomer wants to make a shielder, he really needs to try the strenght, agi and balanced builds. The subtle differences are what makes you like one build and dislike the others.
About what to do with spare points, I think putting them in throwing (yes it's lame but wait till the end of this sentence) and putting a few PT to carry war darts can be a good idea. You will often find yourself forced to run behind fleeing enemy archers, which can be extremely frustrating and dangerous. A few war darts can fix things up quickly, without ruining your build.