It is a matter of what you like and how you like to do things. I would ask myself, what fx into what fx. For example, "do I want to modulate my reverb, or reverb my modulations". Typically I would put modulation first, but there is no reason not to try different ideas.
Asking the question "what do I want to achieve" is a good starting point. Then trying to understand how the fx works and what it can do and can not do can help to move the process forward. Although it is useful to understand the physics (just like music theory is useful), hands on experimentation is necessary. (The physics can help you see how things are connected).