I don't claim to have deep bond market insights, but I have most of my bond money in AGG.
https://www.ishares.com/us/products/...ond-market-etf
BND is essentially the same fund. I have some TIPS, but I just don't see raging inflation in the future as baby boomers start dying off (I'm at the tail end of the boom) so I only have a small allocation to TIPS.
I don't have any international bonds. Don't like the currency risk, which I suppose can help at times as well.