If you are afraid of losses, it is enough to choose 1 mixed+1 bond+1 currency. The risk is minimal, and the income can outperform the bank interest.
Not very afraid of losses, 1 stock+1 mixed bonds or currencies, the risk is relatively small, and the income is slightly higher than the above.
If you are not afraid of losing money at all, you can have two stocks of+1 index type. The bull market gains the most and the bear market loses the most.