Well I guess the main one would be avoiding hypos.
So regular testing especially in the early stages of modifying your diet.
Maybe join one of the low carb T1 groups like Typeonegrit where you'll probably get more specific advice?
Yep, I agree with the above. Also you will need to adjust your insulin regime accordingly and don't forget about the basal. People sometimes think it's all about if you eat low carb/keto then all you have to do is reduce your bolus. Even without eating anything you still (obviously) need the basal to be working or your levels will be high regardless of diet. If you find your numbers drop to the 4's, don't assume you can always leave them like that (depending on circumstances) as you never quite know when your basal will kick in and a hypo can come on quick. x