You can make high-quality searches in IPRally without ever touching a graph, just using the automated claim-to-graph or text-to-graph functionalities. However, in many cases, manual editing allows you to quickly generate new and modify existing searches.
Working with the graphs works best when you think about it as a notepad memo with bulleted lists.
You can:
create new items with Enter (sub-item) and Shift+Enter (sibling item)
indent and outdent items with Tab and Shift+Tab
move items up and down with Shift+Up and Shift+Down
link features to relations by selecting them from a list of suggestions that appear as you type.
Otherwise, it is just typing in your thoughts in English language.
If some operation is allowed, you can do it. If it is prohibited, you just cannot do it. Simple!
Indenting and outdenting items, i.e. their parent-child relationships, will have an effect on the search, as those relationships have a technical meaning.
Shifting items up and down will not affect search results but can make the graph more logical and readable.
The search engine is trained with graphs automatically created from patent claims and descriptions. Therefore you'll get best results if you use "patent-like" expressions. But you really should not think too much about this: the engine understands also normal language.
It is more important that you tell the computer how things relate to each other.
To exemplify, this graph
gives you clearly better results than this:
Learn how to edit a graph in this detailed Video tutorial.