This video describing PICO (Population, Intervention, Comparison, Outcome) was developed for the CINAHL nursing database, but the concepts also apply to PubMed. Framing your question in PICO format can help you identify key components of your search.
PubMed and Ovid MEDLINE have nearly 100% of the same content, but how you search them is quite different. You can learn more about searching Ovid MEDLINE from UBC Library's tutorials.
Ovid Medline allows you to:
Additionally, drug terms are handled quite differently in PubMed and Ovid MEDLINE. PubMed makes more use of Pharmacological Action terms. For more details on drug searching in PubMed, see the guides below.