There's been a few threads on this subject in the past that are worth searching for.
I work in the insurance industry (although not on the "personal lines" side, which this would be). My comment would be that I think you're currently doing the correct and likely most economically prudent thing: insuring via your homeowners policy. That said, you may want to go with a "higher end" insurance company or insurance product.
My watches and wife's jewelry are insured via a rider - i.e. a separate off-shoot of our main policy. The rider has advantages like having no deductible, insuring all pieces to full replacement value and also requiring no requirement to declare specific watches or their value so long as total value is below $30,000.
You will need to speak to a broker in order to find the policy that fits your specific needs - you don't pay for their time - they're given a commission by the insurance company. I can't legally give you advise but i will say that insurance is like every other product: you get what you pay for and i'll tell you what i use for insurance.
I insure via a company called Chubb (I do not work for Chubb - in fact they're a competitor of mine). They are well-known for excellence in personal lines coverage - although they can potentially cost slightly more. Other insurance companies also offer "higher end" policies if you specifically request them - they tend to offer coverage frills along with providing a significantly easier and less antagonistic approach in the event of a claim and will offer higher jewelry limits without appraisal. I had a Tag Heuer Monaco stolen at the beach a few years ago - I'd bought it on a forum for $1,600 but I had a Chubb cheque in my hand for $5,000+ within two days as that was the replacement value quoted by the jeweler adjacent to my office - again, you get what you pay for from your insurance company. Chubb had no appraisal or list of what watches i had - i believe they did ask me if i had any photos of me wearing the watch (which i provided - ALWAYS good to have some photos of your watches).
Finally, keep in mind a few more things:
1) Insurance brokers aren't all equal. Shop around and see what they offer you. They're paid based on a percentage of the premium so it's no skin off your back having them send you a quote;
2) Price isn't the only thing to consider - you can have wildly different terms in a given policy. So cheap may be just that - crappy, cheap insurance (check things like deductibles, limits, territory the insurance covers, whether you're covered for "mysterious disappearance" (insurance term for "i left it somewhere and now can't find it"); and,
3) you're simply a number to an insurer - the more premium you can promise them, the better the deal you typically get. So it's typically best to insure everything with one insurer - home, auto, any business you might have, etc. Frankly, if you're insuring a house and a car with a company, your watch collection likely isn't all that significant of an exposure for them.
Hope this helps.