I have a G10 w/ YS110a i shoot full manual and the settings I use should carry over to the G11 fine or at least give you a starting point. I have 3 setting modes I move between and then tweak shutter, aperture, and iso. I use C2 for close-up macro subjects; C1 for some macro, mid-range and reef shots w/ strobe; and M for available light shots in shallows, reefscapes, and whalesharks.
To set, first set C2, then C1 and M:
C2 settings
go into M mode
flash, macro on
set 1/250, f7.1, center weighted avg
Focus frame small
Func Set
White Balance: Custom2
BKT-Off
Flash Output: Minimum (1/3)
ND Off
RAW
Menu:
AF Frame: FlexiZone
AF-Point Zoom: On
Servo AF: Off
AF Mode: Continous
Digital Zoom: Off
Flash Control: Minimum, First Curtain, Red-Eye Off
Spot AE Point: Center
MF-Point Zoom: On
Safety MF: On
AF-assist Bean: On
Review: 2 sec
Review Info: Off
Record RAW+jpg: Off
AutoCategory: On
IS Mode: Shoot Only
Converter: None
Custom Display: check Shooting Info, Grid Lines, Histogram
Shortcut button: Custom White Balance 2
Save Settings: C2
C1 settings
set 1/400, f4.5, center weighted avg
flash, macro on
Focus frame regular
Func Set settings same as C2
Menu:
same as C2 except
AF-Point Zoom: Off
Save Settings: C1
M settings
set 1/100, f3.5, center weighted avg
flash, macro off
Focus frame regular
Func Set settings same as C2 & C1 except
White Balance: Custom1
Menu:
same as C1 except
Shortcut button: Custom White Balance 1
Usage
I set the white balance as depth and light changes, also when changing ISO.. so I'm constantly setting white balance.
In C2 strobe power is usually set between 11 to 3 o'clock position as indicated on power dial. Turn on focus light. Position strobe closer to lens and try to kiss the subject with flash. Shutter speed ranges from 1/125-1/320, aperture f6.3-f8, ISO 80-200. Get close and maybe zoom in.
C1 strobe power is from 3 o'clock to full, usually at 6 o'clock to full. Position strobe away from lens. 1/80-1/500, f3.2-f5.6, ISO is usually 80-100, will use 200 at depth.
M is available light by default, turn flash on to strobe.. turn macro on for subjects. 1/60-1/320, f2.8-f5, ISO 80-400, 400 is mediocre for me should be better with G11.
The M settings aren't saved, most recent used are, except for macro mode not sticking. C1 and C2 settings will revert back unless saved.
Get some Eneloop or equivalent batteries for strobe. I'd consider a Fantasea Big Eye lens too, extends the angle and matches well with strobe.
Have fun!