Congratulations on becoming a 'Biker! Make sure you get over to Bob's HyperBike group, if you haven't already. I have made several additions and changes to my rig since getting my 'Bike a little over a year ago. Some I added because of the competitions I do, some because I just like my comforts.
To my harness, I added quick release on the tugs, and "reversed" my breeching holdback straps. My holdback straps now stay attached to the shaft of the 'Bike, and I have a good, sturdy brass clip that snaps to the ring to which the holdback straps used to be attached - again for a quick release. (I did this to my EE cart as well, as a safety feature).
I got the smaller of Bob's two seat/saddle/spares bags. It is PERFECT for us. I frequently put in a peanut butter and honey sandwich (often shared with PJ) two water bottles (also shared), some of PJ's fave cookies (not shared - he gets them all). For competitions, I keep a spares kit in it and pin my numbers holder to it.
This Christmas, Mom gave me a full seat cover. While it is actually designed for a mower tractor, and is a little big for the 'Bike seat, it was very warm driving in a mile-high, snow laden winter. Now during the 100 degree summer, it is keeping me from burning my legs in shorts. It does have pockets for water bottles, but it not has handy as Bob's. The biggest advantage it has is that it covers the entire seat back (with Bob's bag under it) and the seat, keeping all nice for competitions, and for attaching my smv triangle on.
To my 'Bike, I have added reflectors (needed for events, but also a good idea driving on the road). I added a bicycle computer because for conditioning for CDEs and HDTs, we have to move particular distances at given speeds, and PJ is not the fastest mover in the world. Just like on a bicycle, I can tell if he is moving fast enough, and if we are getting our distances in. This is actually my second installed bike computer, the first having gone missing, I believe, in a water hazard schooling venture. Between the two, I have a little over 500 miles on my HyperBike!
I have also discovered an extra good point for the bike computer:
As a member of American Driving Society, one is eligible for their Hours to Drive Program. No competition, just logging in the number of hours driven. Just for fun! Now, when I drive, I check the clock on the computer and log it in, then log it out when I quit. The bike computer clocks KPH, distance, drive time, overall odometer and a clock. It's fun and it kind of encourages you to get out
Susanne is perfectly accurate with the over the top approach to obstacles on the trail. You do want to "bench press" your 'Bike at home until your horse is comfy with the concept. And don't put the reins over your head, plowman style. I wasn't aware I would ever have to mention that until I watched someone lifting their EE cart over a boulder (the 'Bike cleared both height and width, so I didn't even have to leave my seat
Around here, because ATVs and quads are so big, and folks get tired of them ripping around, but don't want to eliminate equine, bicycle, or runners, we see a lot of gates with a portion of the gate "v'd" out. Horses can step over the bottom rail, cyclists can lift their bike over it, runners and walkers jump it (bassetts go under it). Most of the time, I can just lift my 'Bike over them, but there are a couple that I actually have to twist, or cant the bike a little sideways because it's wider than the open part, so I practiced picking up the 'Bike and turning it nearly 90 degrees. Teaching your horse to pivot turn is good to do also.
My secret fave part about the HyperBike is I get to drive peacefully and blissfully alone whenever I want. It's like milking a cow, no one bugs you!
Enjoy, enjoy!