1. COMPUTER AND COMPONENTS
To get success in this game, you have to play on a well-deserved computer that will not return doldrums on FPS in dynamic situations or during spreading points. In addition, a good monitor is essential, it should be not less than 144 Hz and have fast experiences. You will also need good mechanical keyboard and mouse - they are important for the good movement. As you are getting much more comfortable play with a good "machine".
Try to find the most friendly settings that will do for you - scope, sensitivity, resolution and so on. Many professional players are experimenting with it regularly. There’s no need to download the player’s config, install it and try to "adapt" to it. You can test several options and choose the best one, or change it for yourself. Your joy is the main thing.
3. AIM TRAINING
Aim is a very important thing in CS:GO, so you need to practice headshot AIM training as often as possible, constantly improving your skills. You can try to play offline on aim_botz or just play on the DM-servers. By the way, earlier my teammate v1c7oR has given tips on the topic of training. You can read them via this link.
4. GRENADES STUDY
Try to get up as much as possible scatterings, because it is a very important part of the game. Fortunately, now there are a huge number of ways. Watching the professional matches, you can record the rounds with an interesting grenade or scattering. Then just download the game demo and study it in details. In addition, YouTube has great collections of simple and effective grenades that are guaranteed to make your game better.
5. DEMO AND PRO GAMES WATCHING
Demo and professional matches watching is also very useful, because you can always get up new things and tricks from the game besties. You can choose a player whose playing style you like and watch demos in third person. I am sure you will find something that can improve your game.