>>/3288/
> I create and share a bunch of stuff so I can't tell if a purple cat is from me
Yeah I know just mentioned. Sometimes it's just some "energetic turbulence" that causes entities to appear. If they don't cause too much trouble I give it the same importance as a bird flying over my head. Which I either don't care or WHAT IF THIS WAS A SIGN I MUST FIND OUT MORE.
 >>/3300/
> tentatively trying to connect to "my guide" lately
I think you need the "advice" to not force your guide into a form but let it happen on it's own. First it will be like some faint whispers. Oooooor if you are the person that just wants a voice to violate his "thought palace" then make a form that it can inhabit. As BO said it really depends on the person.
> Do you test it in some way
Yes
> without becoming overly cynical about it
You will literally stop caring about "how accurate" things are for multiple reasons. First of all the "false expectations". Those "expectations" sometimes make an "impossible criteria" that entities can't match. Hard to explain. It's an "energetic reason" syncing is not just "Information share" but the "type of energy" that "carries" the information too. The best example is literally software compatibility. Sometimes you need an "extra software" that does the "converting" and sometimes you just need to adjust the "settings". Depends on the people and the entities you try to channel. Oh and the funniest part. Not seeing the "same thing" is sometimes beneficial. Your "individual perspective" can notice things that the other person cannot. And lastly the concept of Qualia. Even in IRL you cannot be sure you are seeing the same thing as the person standing next to you so only bother as much with it as you feel the "need" for it. Beyond that is just "hair-splitting".

Also about guides. It's not necessarily "one". Different issues can be tackled from different perspectives. 
> I can't help wonder if I'm making it all up
We are literally "making up" reality. But don't worry about this. As you progress you will have a lot of questions like this.