Every direct line is different depending on the primary source documents needed to prove each link. It is a great idea to join DAR which will give you an idea of the documents required to prove a lineage for a lineage society.
Going up a previously approved lineage is always easier. When you are more experienced you can do unproven lines and even correct incorrect previously accepted lineages. Naturally do not use a lineage you know is incorrect even if the society accepts it.