Do you proactively send messages? Women seem to have better luck when they "make the first move," as seeking out and directly approaching minimizes the chances a great match will not see them, or will fail to send a message due to lack of courage ("she's way out of my league; I don't stand a chance"). If you can't think of anything to say, then something as simple as, "Hey, I'm interested. Shall we parlé?" will do, as males usually see a first message as an indication of interest, not a demonstration of personality. If you want to take it a step further, try to guess their personality type, then mention something someone with that personality type would find interesting.
I'm surprised you find accurate matches with 100 questions answered. A better approach would be to answer 300-500 (or 1000, if you dare) questions, then delete any that aren't very important, somewhat important, or one your matches would care about. And even with somewhat important questions, if one isn't really relevant, delete it.
Many (especially women on the site) use the very important option liberally, but making something that's not a core need or an absolute deal breaker very important only lessens the value of questions that really matter. For example, if you've answered 5 questions, and they are all very important, someone's match % is lowered by 20 with each "incorrect" answer; however, if you've answered 50, it's only lowered by 2 (I suggested clearing out a little important and irrelevant questions for the same reason).
If a question has an equivalent filter or profile field, answering it is likely a waste. For example, most mark "What's your deal with harder drugs (stuff beyond pot)?" very important, but there's already a "drug use" filter on the browse matches page.
If your answer to a question isn't in line with popular opinion (you think homosexuality is a sin, for example), or if it's to a question that's polarizing, then it's good to add an explanation.
With a good set of questions answered, it's likely you'll begin noticing a lack of compatibility when match percentages dip below 75% (or enemy percentages hit 20%).
You should give a short yet complete summary of who you are on your profile. You shouldn't necessarily use an adjective list (smart, quiet, easy going, etc), as those aren't very descriptive, but should instead tell a story (1-2 paragraphs) about yourself that demonstrates who you are. Or you can demonstrate who you are, then summarize with (up to 3) adjectives at the end. Many make the mistake of talking about what they like and what they do, as though that's who they are. Don't do that. Talk about yourself explicitly. It's great that you enjoy long walks on the beach, and traveling the world immersing yourself in new cultures, but you've essentially stated two interests, not who you are.
You should be explicit and direct about core needs and deal breakers when mentioning what you're looking for in a partner. After reading these 1-2 sentences, a potential match should have a clear sense of what you're looking for, and if it they need to bow out.
Your self-summary gives a sense of who you are, but the magic happens when you share interests, hobbies, favorites, and passions. Think about it. If you read through other profiles, you'll notice you reach the end, are interested, but have nothing to initiate a conversation with ("I'm interested in this person, but WTF am I supposed to say?").
While you want to state more than 1 or 2 interests, listing more than 5-10 is excessive, so try to pick your strongest interests/passions, especially ones that aren't common. For example, many like Game of Thrones, so stating it as an interest, unless you're obsessed with it like a Trekkie is with Star Trek, is almost like saying you're "outgoing, fun, and easy-going" (so generic it doesn't register when read). If a core interest is also very common/popular one, you should explicitly reiterate how serious you are about it, lest you sound generic.
Every section in your profile is an opportunity to share more of who you are, to show how you're unique/special, and to demonstrate your style of humor. Waste not. For example, in listing 6 things you can't do without, avoiding generic meaningless things like family, friends, air, cell phone, internet, etc. Everyone says that. Everyone knows you can't live without air. That said, if you can't come up with something good, it's better to leave a section blank, than to have it filled with crap.
When writing the "message me if" section, you should focus on showcasing humor, and on enticing potential matches to pull the trigger, not on making a bulleted list of negatives/turn-offs.
Pictures are another opportunity to show your personality, style, interests, and what makes you unique/special. They should be high quality, well-lit, and varied. Your first picture is shown on the match results page, so it should be your best and should clearly show your face. At least one picture should give an isometric view of your full body, so it's clear what you look like. If you're not certain which pictures to use, ask the opinion of a few people, as it will be obvious to them.
When browsing matches, I highly recommend selecting "located anywhere" in addition to searching locally, as great matches tend to be all over, rather than concentrated in any specific place.
