I tend to feed my dogs in their crates and leave them alone. If I have to reach in to add something to the dish or realized I put the wrong dish in with the wrong dog they are all fine.
I did have one female that was food aggressive (growl). She was still eating with her litter mates at 9.5 weeks when I got her so not sure if that created the issue. She started growling at me at 3 months. I tried different things to fix the issue, but found that just leaving her alone worked best. I could take anything from her at any time, but usually just left her alone to eat.
Lisa Clark Zu Treuen Händen SG1 Deja IPO3 AWD1 KKL1 B/HOT, SG Elena IPO1 KKL CGC B/HOT, LB IPO2 KKL B/HOT (the ugly little sable), Donovan IPO1 TR2 AD and gone, but not forgotten: Vala SchH3 AWD1 FH2 CGC B/HOT, Nike SchH1 OB1 TR3 AD HOT, Treue SchH3 CD CGC HOT