I suppose that you already know how to use them. Let me tell you the difference between them. In most case, '地' and '得' are in the same. You can use whichever you want. All you need to do is changing a suitable adverb. Such as, '喝得慢' vs '慢慢地喝', not '慢地喝'. When the word behind 'de' is '太', '真' and '很', we just use '得'. Such as, '喝得真慢', '喝得太慢' and '喝得很慢'. It sounds like that 'how could he drink so slowly!' If you want to use a sentence to descibe a word. Such as, '他激动得说不出话'=='he was so excited that he could't say a word'.