To get that perfect glowing tan you should first make sure that your skin is not dry.
Exfoliate dry dead skin and apply a moisturizer.
Before sun exposure make sure you apply the right sunscreen for your skin, it should always be at least 15 SPF, actually even if you are sitting in the shade you should apply sunscreen, because the UV harms your skin anyways.
Drink water regularly, you don't want to get dehydrated!!
Do you burn easily?
If you burn easily then you shouldn't be staying in the sun more than 25 to 30 minutes straight.
remember to change sides every 10 minutes, this will ensure an overall tan.
If on the other hand you don't tan as easily as desired, use some tanning oil. Coconut oil has been proven to be the most effective.
Growing up we used to mix baby oil with oxygenated water ... DON'T DO THAT!
When I think about it, I don't even know if it was effective or not. I know oxygenated water adds highlights to your hair for sure, but as for the tan I'm not so sure. We used to have a dark tan because we lived by the sea, we were constantly in and out of the water.
By the way, the best way to tan is to have a dip in the pool or the sea every 15 minutes, just to freshen up so you can bare more sun...