I think that developed countries, if they are going to give aid, should do so bilateral ways. I think that directly works best. There is less room for loss and mistake if developed countries helped more directly rather than through international organizations. Multilateral works too, I just think that bilaterally is better.
Yes, countries should give aid bilaterally, because it allows them to have more oversight. Through an international organization, the giving country does not have enough say over where their money goes. They also cannot effectively impose conditions that are intended to benefit the nation being helped. It is better to give bilaterally so that giving can be monitored.