Observing Fine Details

A key part of being able to make your games have that ‘polished detail’ to them is the ability to learn what others are doing, take a look at the latest AAA title in the genre you are working on a for example if your working on a first person shooter take a look at the latest battlefield? or call of duty? or if your working on some fantasy role playing game look at final fantasy or some other AAA rpg.
The developers of these AAA games have spent millions of dollars refining their techniques and they put them right their in front of you to learn from if your looking to improve your games overall feel try emulating some of these tactics.
Emulating Polish
No one ever said that you needed a degree in game art to create amazing games so lets copy what the AAA titles are doing. Lets assume we’re working on some FPS game right now what could we do to achieve a higher level of polish? Firstly lets start making sure our controls feel great, Play some COD or Battlefield 4 and try to get your controls feeling right make sure your players are moving with a similar amount of force and that your transition from walking to running occurs at a similar level, Ensure your character stops a similar amount of time after releasing the game pad stick or keyboard.
What about visually? well there’s a stack of tricks these developers use to give their games amazing level of detail. More recently developers of shooters have moved towards applying layers of ‘dirt’ to the in game camera when the player gets hurt or entered some dirty dusty area.

Add some Depth utilize things like camera focus to add Bokeh and utilize color grading to help make your scenes lighting and details pop more.
Colour grading can not only be used to help adjust the colours in your scene to get a better overall look and feel but it can be used to simulate times of the day and seasonal weather effects such as the bright white glare of summer, the cool blues in winter orange hues of fall/autumn and bright days of spring
Shaders
These play a huge role in a games overall look and feel if your engine supports shaders then you are in luck there are plenty of resources online that teach you how to write shaders from scratch but depending on your engine you may have access to hundreds of amazing visual effects. Take a look through your engines asset store and see if you can find them otherwise if your interested in writing your own shaders from scratch there are a great reads that you can pick up on Amazon for a bargain such as the GPU Gems (1, 2, 3) series quite old but the concepts mostly are still relative to todays games and another really good one is called Real-Time Rendering which covers more than just shaders but still is an amazing resource in creating polished works please note that creating shaders is not for the feint of heart and usually requires a vast knowledge of game development and software engineering