Some of the “hidden” features I love most are
1. A report for all your known ancestors within 2,000 years http://wikitree.sdms.si/function/WTWebAncestors/errors.htm?WikiTreeID=Roberts-7085 Just replace Roberts-7095 with your WikiTree ID
2. A report of all the males with your surname who have Y-DNA tested https://www.wikitree.com/index.php?filterId=&filterType=yDNA&title=Special%3ADNATests&s=ROBERTS&order=name
Just replace ROBERTS with the surname of your choice.
3. The ability to find portraits of your ancestors and find your ancestors who have descendants who have been Y-DNA or mtDNA tested https://www.wikitree.com/treewidget/Beaufort-1/899
What can you share?
For me the things I really enjoy about WikiTree are not that hidden. But just the things that make it great and easy to use.
For example, just the basic profile creator, it is easy to use and fill in all the boxes and edit information later. On the other genealogy websites I use like Geni, FamilySearch and Ancestry I feel like it is always more of a challenge to enter in the data and have it come out looking like you want it to. At least you always have to click a bunch of icons or boxes and wait for things to refresh. So I enjoy the editable wiki approach to genealogy profiles.
Also I really enjoy the G2G forum and the ability to "Ask a question" tied directly to a profile. This is a great help as there are usually other skilled genealogist willing to help look up information on a profile I may be having difficulty with finding out certain information.
Then of course the Relationship Finder is way cool and much more robust then the similar tool at the other websites. Allowing you to check the connection between any two profiles, not just your profile to others.
Lastly there is a cool tool I have found outside of WikiTree where you can upload your GEDCOM file and it makes a nifty family tree graphic for you. Check it out at http://learnforeverlearn.com/ancestors/
About those nifty TreeWidgets...
Last year, when I registered a one-name study with the Guild and built a for-purpose website, I wanted to know what options I had for TreeWidgets I could use there. So I went hunting...and tried a whole boatload of ID combinations. I've not used most of them since, and have not gone back to confirm the others. So current functionality not guaranteed. I may come to regret this, but it won't be the first time. :-)
(Edited: Well, shoot. I used "XXXX-1234" as a profile ID in the examples below, and that created a monumental number of erroneous links because...duh...that ain't a valid WikiTree profile. So here's the list using an actual profile ID.)
TreeWidget list ("embeddable" and "not embeddable" refer to inserting the widget on an external webpage or blog); replace "Threlkeld-241" with a valid WikiTree profile ID: