Here are few skills that you can apply while playing dota
#1 Lane Control
One of the important things in early game is Lane control to gain an experience and gold advantage on the enemy. It can be improved mainly through playing against pro or better players or observing professional matches. As well as what the enemy can do to you are key factors in gaining lane control, try to improving your knowledge of which items are the best to used.
#2 Supporting
If you play dota while you are still noob or newbies nad need to more practice, the best you can do is try playing support. It may be the carries that do tons of damage lategame, but it's the heroes that let them get that farmed that really make the difference. You can improve your support by learning how to ward effectively and warding often, playing support heroes with items like mekansm and guinsoos, and focusing on letting your teammates farm. Remember, don't keep feed to your opponent which give him free to kill you.
#3 Farming
Farming is important to gain gold and experience, it can be done by killing lane creeps, neutral creeps, heroes and Roshan. Maybe to killing heroes is an hard and inefficient way to farm and Roshan is very situational, the best way to farm is by killing creeps. Try to practice last hits timing, and also improving your lane control and map awareness so you die less and make your lane easier to farm, along with shutting down enemy heroes.
#4 Ganking
And lastly is Ganking. It is one of the easiest but most often neglected strategies. To make gank effectively, knowledge and teamwork are needed and must do lots of practice. You will most likely develop a sense that tells you to go in or get back, this will be know after playing gank heroes for a long time. You need to think whether you can win the fight under the current circumstances, and take into account the unknown variables.