You don't get to determine whether or not you're a trusted advisor. That's something your clients must decide. All you can do is behave in a way that influences how your clients view their relationship with you.
A trusted advisor brings his clients new ideas, while a salesperson calls on his client when he has the need to sell something. A trusted advisor brings her clients new ideas regardless of whether or not she has something to sell.
A trusted advisor has valuable subject matter expertise. He knows his business, he knows his client's business, and he has enough general knowledge about how things work to offer advice worth taking.
A trusted advisor values the client relationship more than the sales transaction. A trusted advisor never puts a deal before a relationship. She would prefer not to make a sale if the relationship might be damaged by it in any way.
A trusted advisor is accountable for outcomes outside of what he sells. A trusted advisor finds a way to own outcomes that have nothing to do with her product or service. It might be general business advice, for example. It might be advice on strategy, marketing or how to sell. He helps his clients wherever and however they can and doesn't limit the value he creates to what he sells.
A trusted advisor has a personal relationship with her client. This doesn't mean she has a friendship (though that is a possibility). Her relationship with her client is built on value.