Traditionally bonds and stocks move inversely: stocks are higher risk and correspondingly higher returns. But of course they have to add up to the overall economy; fundamentally you should expect to make more money when the world is being more productive and less money when the world is being less productive, and any investment that doesn't have that behaviour is going to be artificial and disconnected from actual productivity, making it unlikely to be a good bet in the long run. (See Buffet's comments about a gold cube). If you're investing for more than 10 years, the best thing is not to worry about recessions: they're part of the cycle, and even out in the long run; just buy and hold and eventually you'll come out ahead. If you're investing with a particular deadline less than 10 years in the future (e.g. as you get towards retirement) then it's traditional to shift your portfolio towards lower-risk, lower-return investments (indeed government bonds as you suggest); some retirement accounts do this "automatically".
Traditional advice is to invest largely within your own country so that you're not taking on extra currency risk, to keep a certain amount of cash/gold/what-have-you just in case of a huge general crash, and to get appropriate exposure to property. There are two contradictory schools of thought on this: 1) treat it as an asset class, hold a similar proportion what you hold in stocks/bonds 2) you will need one home for the rest of your life, ensure you have exactly one home's worth of exposure to the property market, otherwise property makes no sense as an investment for the same reason as the gold cube.
There are only a couple of free lunches in investment: tax efficiency and low fees. So those are the main places to look to optimise: your local legal environment will probably offer various tax-advantaged forms of savings to encourage particular kinds of saving (e.g. retirement accounts), and while most funds will have average performance in the long run, a low-fee fund means you'll keep more of the benefits (if you're in the US, Vanguard is commonly recommended).