Mobile is good as it has no business premise and therefore no overhead. It will pay to have a vehicle that you can legitimately claim to do your bookwork out of, on the move, to prevent any office overhead. I then made certain I always had a usable classic available, even if I never used it, as then the entire budget of costs of the van can be put through the business. Why, after all, would you take a works 'van' to take family, or special friend, out when you have a beautiful MG Magnette, or Ford Capri, to use.
Insurance I cannot really advise on as I was doing Courier work and trade in cars, mobile repairs and moving them by driving, a more expensive policy, I expect. Of course I did have a premises but it was not for public access and I took a risk with a separate general storage policy. Having done the items in the above paragraph you have illuminated two liabilities from insurance.Premises and office. It should save a good deal on overhead costs, plus a little on insurance.