A recent enquiry from a LostCousins member prompted me to put together this piece of advice…..
I don't add someone to my tree unless I'm convinced that they're a relative of mine.
Citations don't prove anything but they do remind you why you thought someone was a relative of yours, and they allow others you might share the tree with to understand your logic. So they're a necessary but not sufficient condition.
Similarly, finding other trees online that show the same information doesn't prove anything - even if it has multiple citations. Many mistakes are made simply because the wrong information is more accessible than the right information, so if one person makes the mistake, the chances are others will too.
My family tree program allows me to record people and families who have a possible or probable connection to my tree without actually connecting them. There are lots of families whose details I recorded over a decade ago, but have yet to be able to connect to my tree. Having them present, but not connected, is extremely useful; one day I may be able to connect them - perhaps I never will - but being able to record information about them as I find it is very useful.
The program I use also allows me to connect someone who I am certain is an ancestor of mine, but where no proof exists (perhaps because a page is missing from the baptism register), with a different-coloured line, to remind me that I need confirmation from another source, possibly DNA.
If the family tree program you use doesn't allow you to do both of these things (albeit in a slightly-different way) you might want to consider changing it for one that does.
Never use an online tree as your main tree, and never post information online unless you are absolutely certain it is correct. Ideally never post a public tree online.
When it comes to adding relatives to your My Ancestors page at the LostCousins site the situation is a little more relaxed. There are times when it simply isn't possible to identify the right person on the census, especially someone who has recently left home and is working as a servant, so I introduced the 'possible relative' relationship. It's not intended as a replacement for research - it's designed for those situations where having tried everything you can't find the answer.
I hope this helps, and encourages you to complete your My Ancestors page so that I can start connecting you with the many other members who are your 'lost cousins'. Much as I like to be able to help and advise members, I can't possibly do as good a job as someone who shares your ancestors and understands the challenges you're faced with.
Hope this helps,
Peter
Note: the main family tree program I use is Genopro, but whilst it does what I want it's not necessarily the best for you; Family Historian is a very powerful program (and it was written here in Britain) - if I was starting from scratch it's the one I'd go for. Unfortunately I can't advise members on family tree programs, not even the two I've mentioned, because it's a very personal choice - what works for me may not work for you - but if a family tree program is worth buying they'll almost certainly offer a free trial version.