Guitar:Anyone Can give me tips on tapping ?

Hello, I Need people to give me soem tips on tapping techniques or a.k.a Hammer on pull offs .... I have been playing for almost 3 months .. And i still cant do that quicky like .. i can make hamemr on pull offs but when it comes to swtichins or doing them while sliding across the string ,,, i find it really hard .. Any tips ?