Before you start trying to slide things, you've got to learn how to bonk. Bonking is merely the act of ollying up onto some object, tapping it and then riding away.
Bill McCaffray, one of the early advocates of bonking and sliding, or as he puts it, "just using the natural terrain of the lake," recommends learning to bonk with a little orange floaty buoy - something round and soft - because it is safe. McCaffray says the most important thing is to learn how and when to ollie.
"You want to have your timing so you can ollie and tap the buoy as you go by. If you can't do that, you won't be successful on a slider."
McCaffray thinks riders should put more variety into their sessions by bonking buoys. "It's an element of technical riding. More than anything, it's use of terrain. We have buoys, so when we ride, you can jump the wake and tap them or pull out and ollie them. I don't think ollying little buoys is unsafe. Metal channel markers are pretty dangerous, though."
There really are two ways to bonk a buoy. The easier way is to do it ollie-style, where you ride up to the buoy outside the wake and just hop up, tap it and ride away; the harder style is where you cut at the wake, get your air and bonk the object as you fly past it. This second style will take you awhile to learn because it's hard to time the hit and you can't adjust your direction once you are in the air.
To do the first type, Marks explains that first, you obviously have to know how to ollie - which is just a bunny hop. Cut out heelside, and drift for a second to make sure your board is flat. You want your board flat because any time you are edging you are turning, which throws your axis off once you get in the air. Compress down slightly then pop up, keep your handle down low and in to your body, and that's it. Timing when to jump is the key. Once in the air, try to bonk the object with the nose of your board. If you want to bring it to fakie, just pull the rope into your back hip with your back hand.
The second and more stylish way to bonk something is to have your driver approach the bonk object so it is on the opposite side of the wake from you. Take a good, hard toeside cut at the wake, leaving yourself about 15 or 20 feet of travel room to the buoy. In mid-air, throw it to fakie and aim to hit the top of the buoy with the nose of your board, then land to fakie. Since you will be hitting the buoy with the nose of your board after you pass by it, this style is much safer than cutting at it and aiming to hit the buoy square with the center of your board.