Cutting should not usually be taken from the end of a branch nor the top part, rather, in between. Testing and experience will allow you to select at what stage of maturity each type of plant will root best. Some cutting from the same stock plant may root while others may not. There may be a 'best time' to take cuttings from the plant. Rooting of cuttings is affected by many variables.
Some plants have different rooting ability at different times of the year.
A few weeks difference in taking of cuttings may produce success or failure. Woody plants are especially influenced by timing. After a certain age, often years, some plants may even have difficulty producing cutting viable to produce roots. Some plants produce better rooting when cuttings are taken from juvenile parts of the plant. When taking shoot cuttings from the same stock plant at the same time some cuttings may have different rooting ability.