Load spike protection for Django Channels
DDoS = Distributed Denial of Service
The 'Distributed' part is the key: you can't know you're being attacked by 'someone' in particular, because requests come from all over the place.
Your server will only accept a certain number of connections. If the attacker manages to create so many connections that nobody else can connect, you're being DDoS'ed.
So, in essence you need to be able to detect that a connection is not legit, or you need to be able to scale up fast to compensate for the limit in number of connections. 
Good luck with that! 
DDoS protection should really be a service from your cloud provider, at the load balancer level.
Companies like OVH use sophisticated machine learning techniques to detect illegitimate traffic and ban the IPs acting out in quasi-real time. 
For you to build such a detection machinery is a huge investment that is probably not worth your time (unless your web site is so critical and will lose millions of $$$ if it's down for a bit)
Is there anything specific that can be done to help make a Django Channels server less susceptible to light or accidental DDoS attack or general load increase from websocket/HTTP clients? Since Channels is not truly asynchronous (still workers behind the scenes), I feel like it would be quite easy to take down a Channels-based website - even with fairly simple hardware. I'm currently building an application on Django Channels and will run some tests later to see how it holds up.
Is there some form of throttling built in to Daphne? Should I implement some application-level throttling? This would still be slow since a worker still handles the throttled request, but the request can be much faster. Is there anything else I can do to attempt to thwart these attacks? 
One thought I had was to always ensure there are workers designated for specific channels - that way, if the websocket channel gets overloaded, HTTP will still respond.
Edit: I'm well aware that low-level DDoS protection is an ideal solution, and I understand how DDoS attacks work. What I'm looking for is a solution built in to channels that can help handle an increased load like that. Perhaps the ability for Daphne to scale up a channel and scale down another to compensate, or a throttling method that can reduce the weight per request after a certain point. 
I'm looking for a daphne/channels specific answer - general answers about DDoS or general load handling are not what I'm looking for - there are lots of other questions on SO about that.
I could also control throttling based on who's logged in and who is not - a throttle for users who are not logged in could help.
Edit again: Please read the whole question! I am not looking for general DDoS mitigation advice or explanations of low-level approaches. I'm wondering if Daphne has support for something like:

Throttling
Dynamic worker assignment based on queue size
Middleware to provide priority to authenticated requests

Or something of that nature. I am also going to reach out to the Channels community directly on this as SO might not be the best place for this question.