Relationship between gov debt bonds/ETF and value

Hello all,
Looking at a variety of ETF and bond investments and seeing a lot are based on various governments debt. I’m familiar with gov debt and gov bonds, currency valuations and things like that, but not sure about how these investments respond when:
Gov debt is high/increasing
Gov debt is being paid off/decreasing
Annual bond cycles (some seem to have regular patterns).
I’m after any observations/rules of thumb from the community on these kind of investments!
Thanks in advance