BA4SUA 7.023, 14.023, 21.023 – these are some commonly used values. Because the background noise in the neighborhood is high, SSB (Single Sideband) operation is difficult, and FT8 isn't of interest, CW (Continuous Wave) is a more suitable mode.
BG5CVB I usually just pick a location based on my mood (and also whether there are people around), since shortwave radio isn't really about reliable communication. I can call from anywhere near the Activity Centre. .010, .016, .018, what date is it today? Use zeros and then a decimal point.
BA4SUA BG5CVB Basically, you find a frequency and then other friendly stations use the spectrum to see if there's a signal nearby and switch over. Is that correct?
FengziLeo Perhaps I'm just not using them enough? When I use the common frequencies, it feels like there aren't many people around. I have to constantly scan the spectrum to find where people are.