You can use the form on this page to contribute new or revised phylogenies. Please select a phylogeny submission type and a citation type. The citability is what keeps this useful to everyone involved, so please check your citations! If you wish to provide code, you should probably check the API documentation.
You can also now directly contribute on GitHub!
Please be sure at least one group already online is included as an outgroup to your contribution. If you wish to contribute search tags, it is simplest to paste a block of code from the source code and insert tags directly as mentioned in the documentation.
No project is ever perfect, and suggestions are always appreciated! Just let me know any ideas / feature requests / etc, and I'll take a look and get back to you.