minikube start
kubectl config use-context minikube
kubectl create ns my-namespace
About half the time this succeeds and about half the time I get an error creating the namespace: Unable to connect to the server: dial tcp 192.168.99.100:8443: getsockopt: operation timed out
Any thoughts?
There's a lot of configuration variation possible with minikube, so I'm going to have to make a bit of a leap and assume you're running pretty close to the default configuration.
By default, the VM minikube runs on Virtual Box, using a dynamically allocated IP address. Frequently it will be assigned 192.168.99.100, but there's no guarantee that it will get this IP, and it can be something else.
Run minikube ip and see if the IP minikube is using is something other than 192.168.99.100. If it is, then check your Kubeconfig and see if the IP address matches.
minikube start usually updates your kubeconfig with the correct IP, so try running that if there's a mismatch and it should fix your issue.