The best advice, get an insurance agent you trust (though some people would say that's an impossible request) and have them review your individual situation to determine the best way to get all your needs covered. If you don't like what they have to offer you, don't buy it.
It took me several tries, but I finally found an agent I like. My homeowners, business, and personal articles policies were rewritten to all be with different companies.
In my agents words "Necessary, no. For the extra little bit a year is it a good idea? Yes." Unless you're terribly unlucky, a legitimate claim on your personal articles policy shouldn't cause severe adverse reaction.
But as she explained, worst case with a large claim on one of my personal articles polices -- I get cut a check and they refuse to rewrite the policy. Unfortunate, but hardly comparable to getting a notice of non-renewal on my homeowners and then finding no other company with cover me.
Just look at the rates -- $3/year posted here for each $100 personal articles, my homeowners is roughly $0.20/yr per $100. Since rates are based on risk, it seems clear personal articles policies have a higher risk (deductibles, size of average claim relative to full policy value, etc. do come into play -- but still a big difference) and thus are more likely to have claims filed. So adding that rider to your homeowners means you're increasing the likelyhood of having to claim against your homeowners.
Keeping the personal articles seperate (in my state and with the insurers I checked with) makes claims on those not count against current or future homeowners -- and they needn't be disclosed on homeowners applications. Obviously claim history is requested on new personal articles policies.
By using one agent that writes with multiple companies, I end up with a rate that's about halfway between everything individual and everything with one company.
Generally no insurer has a policy against writing small personal articles -- it's the agent that refuses. They make their living by writing policies, and it's not cost effective to spend the time to write John Doe-New-Customer a $15 a year policy. If you don't have homeowners or some other policy to start off and an agent tells you it's not possible, just try another. Eventually you'll get one that's willing to do it. Or try larger shops where the agents are more likely to be salaried and don't really care what the policy is.
You'll save money if you do the legwork to buy your policy from an insurance company or agent directly rather than through a firm that specializies in covering cell phones and the like. All they're doing is packaging the many smaller policies and then shopping themselves around on the reinsurance market -- and making their profit in the middle.
And in my experience, the claims process is easier and quicker. When I claimed through a cell phone specialist, I had to jump through falming hoops and still got screwed in the end. My "normal" insurance claims were either done quickly just over the phone, or I only had to fax a police report and/or affidavit and had my check within days.