Last week, a relative of someone I know died. I found it hard to express my sympathy in Russian. That's not something you usually learn. Of course, I told her to "принимать мои соболезнования", but it sounded a bit artificial. Is this correct? What do people usually say?

When you congratulate someone with his birthday, you usually don't say "я тебя поздравляю с Днём рождения", but simply "с Днём рождения". Is this also possible with condolences? "Мои соболезнования" or something?

Also, in Dutch it's pretty common to wish someone "strength" (sterkte) after a loved one has passed away. Is this also done in Russia? If so, how?