What tips do I have?  In business I hear it is Location. Location. Location.  With auctioneers it is Reputation. Reputation. Reputation. There are a few I do not even look at because of past problems. 

There used to be an area consignment auction that had a ... reputation.  I remember being there once where we'd reached the end of the row and were at the augers around the corner.  I was bidding on a conveyor and realized nobody else was around.  I stopped bidding.  The ring man was urging me to bid again.  I told him I wasn't bidding against the guy in the trees, because I was the only one there bidding and it kept going up. I finally bid half what his usual raise amount was and got it.   If he were still alive and online I wouldn't buy from him.

Buyers HATE buyer's premiums.  There's a area auction I rarely use just because of the premiums.  If I buy something there it's because I almost stole it.

Build for a lot more capacity than you expect.  Nothing worse than a slow, frustrating system.  You want someone really good at keyboarding entering data.  They MUST keep up with the activity.  Your system can't be buffering during the auction. And make the sound understandable.  An area site I think just sticks a microphone in front of a speaker.  It's difficult to understand if you have good hearing.  For me it's almost worthless

Make your photos and descriptions worth looking at. A fuzzy photo of a disk with a description "Disk" is worthless. Remember, you are selling yourself and the product.  Make it look professional.

If you are looking at starting an online auction I would suggest looking at Schmid Auction at Teutopolis, IL  ( https://www.bidschmid.com/ ).  They do a very good job.  No buyers premium.  Good descriptions.  Everything handled well. I'm told they have their own site rather than use something like HiBid.  They're consignment sales are totally online.  Having been there, bought and sold stuff there I do not think it could be done in person. Not without multiple rings and at least 40 more acres of parking lot.

I kind of miss the in person auction. But I think their days are numbered.  I can sit at home in comfort in my sweat pants and watch / bid / sell stuff hundreds of miles away in the rain and snow.  The only down side is I don't get as many deals on stuff because I fought the weather and everyone else stayed home.

Oh, one more thing.  Make sure you have all your legal ducks in a row.  Online or not you have to meet all the auction rules and regs of your state.  Being from Illinois I'm confident the state will have all kinds of ways to get money from you.  Vehicles and firearms may require more licensing.  And I'm not sure what happens when you're in one state and the buyer is another.