There are many types of dictionaries such as learner’s dictionaries, general dictionaries, picture dictionaries, etc. Therefore, first identify your needs. Without choosing the right one you cannot meet your language needs.
1 )
Use any dictionary without identifying your needs.
2 )
Only picture dictionaries are chosen by language learners.
Before using a dictionary identify your language needs.
4 )
First use a dictionary, then identify your language needs.