So the proper foot placement for the ollie is with the ball of your back foot horizontal on the tail of your skateboard.  And your front foot centered on your board right behind the front trucks.  You may find that moving your feet around in different positions are more comfortable.  This is fine,  everybody can learn how to skateboard their own way.

An Ollie is basically an upward/forward jumping trick. The name “ollie” comes from the nickname of Alan Gelfand who created the ollie in 1976. The ollie was then modified for flat-ground use by Rodney Mullen in 1982, and it is this flat-ground version of the ollie which is most commonly referred to as the ‘ollie’ today. The ollie is arguably the most important trick in skateboarding because it is the foundation of the majority of skateboard tricks which require lift. When you want to do a trick like the kickflip, when you want to get onto something like a ledge, or down something like a set of stairs, or try handrails, the ability to ollie is a necessity. Therefore the ability to ollie high and with good control is critical to your total skateboarding skill-set.
Slam your back foot down on the tail of your skateboard as hard as you can. At that moment, you want to also jump into the air, off of your back foot. This part is key and takes practice. The trick is in getting your timing right. You want to slap the skateboard’s tail down, and as it hits the ground, jump off of that foot into the air. Make sure to pull that back foot high into the air. It's a quick, snapping motion.
There is no governing body that declares any regulations on what constitutes a skateboard or the parts from which it is assembled. Historically, the skateboard has conformed both to contemporary trends and to the ever-evolving array of stunts performed by riders/users, who require a certain functionality from the board. The board shape depends largely upon its desired function. Longboards are a type of skateboard with a longer wheelbase and larger, softer wheels.
The switch stance ollie uses a similar body motion, but the nollie is subtly distinct: For one, the rider is always moving forward, with the body positioned in a nollie stance--closer to the nose and with the front foot on the nose. Secondly the rider usually postures the body differently so as to compensate for this stance with respect to the forward motion. The rider presses the nose down using their front foot to engage the "pop" motion in order for the board to rise. This is In contrast to a "Fakie Ollie" where the pop motion is performed by the rear foot on the tail, similarly to a normal Ollie, however the rider is traveling backwards when performing a Fakie Ollie. Where in a Nollie the rider is traveling forward with their front foot on the nose to apply the initial force "pop".

The wheels of a skateboard are usually made of polyurethane, and come in many different sizes and shapes to suit different types of skating. Larger diameters (55–85 mm) roll faster, and move more easily over cracks in pavement and are better for transition skateboarding. Smaller diameters (48–54 mm) keep the board closer to the ground, require less force to accelerate and produce a lower center of gravity which allows for a better response time, but also make for a slower top speed and are better for street skateboarding. Wheels also are available in a variety of hardnesses usually measured on the Shore durometer "A" scale. Again like car tires, wheels range from the very soft (about Shore A 75) to the very hard (about Shore A 101). As the A scale stops at 100, any wheels labeled 101A or higher are harder, but do not use the appropriate durometer scale. Some wheel manufacturers now use the "B" or "D" scales, which have a larger and more accurate range of hardness. Modern street skaters prefer medium-sized wheels (usually 51–54 mm), as small wheels with lighter trucks can make tricks like kickflips and other flip tricks easier by keeping the center of gravity of the skateboard closer to the deck, thus making the deck easier to spin. Street wheels are harder (A 100/A 101). Vertical ramp or "vert" skating requires larger wheels (usually 55–65 mm), as it involves higher speeds. Vert wheels are also usually slightly softer (A 98/ A 99), allowing them to maintain high speed on ramps without sliding. Slalom skating requires even larger wheels (60–75 mm) to sustain the highest speeds possible. They also need to be soft and have better grip to make the tight and frequent turns in slalom racing. Even larger wheels are used in longboarding and downhill skateboarding. Sizes range from 65 mm to 100 mm. These extreme sizes of wheels almost always have cores of hard plastic that can be made thinner and lighter than a solid polyurethane wheel. They are often used by skateboard videographers as well, as the large soft wheels allow for smooth and easy movement over any terrain.
Now, I might not be able to skate to save my life, but I can do a little physics. So here's a thought - maybe I can use physics to learn how to do an ollie. Here's the plan. I'm going to open up the above video of skateboarder Adam Shomsky doing an ollie, filmed in glorious 1000 frames-per-second slow motion, and analyze it in the open source physics video analysis tool Tracker.
Here we have an original Z Jimmy Plumer model. It has some handling scuffing from being around for several decades, but displays great. Grip has no holes at trucks which leads me to believe it’s never had any mounted. This is one heavy fiberglass mamma jamma. Get this piece of history at a fair price. I will throw in free priority insured shipping for the con us. Everywhere else at actual cost. Thanks for looking.

Any serious skateboarder will tell you that the ollie is the most fundamental skateboard trick. In fact, it's probably the first trick that you'll learn on your skateboard. They’re great for getting over obstacles, moving around on your board, or just looking cool. Know the right way to move your feet on the board and with a little bit of practice, you can learn to pull off the perfect ollie.
Ohderii Skate Skateboards are made of a High-quality Plastic deck which will not easily break even when pressed over by a car.  It comes with 3.125″ all aluminum alloy trucks, 59mm 78A super smooth PU wheels and ABEC-7 stainless steel bearings.  It is ready to use and you can easily store it in your backpack.  It has an average rating of 4.5 on Amazon.