As a general consumer of travel over the course of your life you've no doubt assumed travel agents only earned commissions and charged nothing for the planning. You'd be correct until now. Many travel agents, and all independent contractors for Jess.Travel charge fees. This is because your time preparing these itineraries demands it. Also, it's because your ideal customer will expect to have to pay you for your time, and also your loyalty. Charging fees means you do not have to steer clients away from booking flights or airbnb's because of the lack of commission. You can simply charge fees for these items.
Some travel planners charge by the travel day, and some charge by the trip. According to Gifted Travel Network, planners charge between $125-$300. Jess.Travel ICs will oftentimes get even more.
Place your fees very clearly on your website so there's no ambiguity. This will also clear out the tire kickers.
Deciding what to charge is another question all together. You're going to have to quantify what you're worth against what your target audience is willing to pay. When you're new, start lower. Get some experience and raise it. At the time of this article, Jess.Travel was charging $99/day for planning, that's up from $35/day at first, then to $69, now $99. We expect that to raise again.
Your planning fees are always your own. You'll never share them with the host agency. For more information on fees (probably more than you want) here is a very long webinar on the topic.