A lot of suggestions will depend on what options you have available. i.e., do you own strobes, tripod, PP software, etc.? If not, you have fewer options, but that doesn't mean you can't make great shots.
I actually really like the light in the rose shot, so I think I'd try to "fix" the OOF issue by:
Use a tripod
Increase your aperture 2-3 stops
Reduce ISO to 200
Use a long exposure with a remote release
If none of that is an option, I'd go ahead and increase ISO. You're generally better off to get a correct exposure with higher noise than to under-expose.
WhiskeyTango