Use e.g. when you are introducing a short list of examples
- There are many good dictionaries on sale nowadays e.g., Chambers, Longman, and Collins.
Use etc. when it is obvious that you are referring to a long list
- There are many types of dictionaries: monolingual, bilingual, slang, etc.
These are very common abbreviations derived from Latin and shouldn't create any difficulty of comprehension. But if you are writing a formal exam, paper, letter, etc. Or your audience might be unfamiliar with their meanings e.g., non-native speakers, then by all means use their English equivalents “such as”, “for instance” and “for example” can substitute e.g. The expressions “and so forth” or “and so on” can replace etc.