Depends on the # & types of abbrevs. & the context.

If I'm desperately trying to write down notes in class from a fast lecturer, I'll abbreviate a lot.

If I'm trying to be concise because of space restrictions, like in a table, I'll abbreviate.

If it's something that's almost always abbreviated, like "etc." or "St.", I'll abbreviate.

I tend to abbreviate names a lot.

Otherwise I typically spell things out.

One type of abbreviation I literally never use is the txt msg spk stuff. You know, like "u" for "you", "4" for "for", etc. That always looked cheesy and dumb to me.

____________________

'Cause when you've given up,
When no matter what you do it's never good enough,
When you never thought that it could ever get this tough,
That's when you feel my kind of love.