I'm doing my family tree and I'm on Ancestry with a worldwide membership. One of the biggest helps
and hindrances is the tradition of keeping names in the family. My dad is John, and apart from his father (Leonard), every other male line son has been John or James. The Johns would names their eldest son James, and his brother James would name his eldest son John, There were more John and James than I could shake a stick at, complicated further by the fact that they often lived in the same street or road!! Often family members would be lodging with relatives (to spread the financial load) so the Ancestry transcribers (who do sterling work, believe me) occasionally added children to another part of the family, or took them away!!
One of the most helpful things family pride often did was to add the maternal maiden name to one or more of the children as a middle name in order to keep the name running (especially if all the original children were girls who would lose the family name upon marriage). Occasionally the maiden name would come from a grandparent rather than the mother, but it is still helpful.
WWI records have been released and they have been helpful with DOB and wives maiden names and where the marriage took place.
The Latter Day Saints have a duty to record all parish records wherever they go for their two-year missions, and there are free websites that you can search for this information.
It's worth checking alternate religious records, or even the nonconformist or non-parochial records for couples who have run away to be together. Bigamy was more common than you think, because divorce was almost unheard of, and prohibitively expensive. Far cheaper to move to another county and start again. This is often why names variations happened - we had a 'Marsh' change to 'March' to avoid debt, and occasionally I would find that a name had been misspelled because the enumerator has misheard a local accent (Cabble was written for Cable, Portch for Porch) and often family 'pet' names were written (Millie instead of Amelia), or a second name would be used if mother and daughter shared the same name.
Sometimes I have had to search by location, and just find the street someone lived in and go back and forth on the 'previous' and 'next' options to find other family members. It's useful if they have out of the ordinary occupations too. I found the railway employer's records for my 3x great-grandfather who was a train driver/shunter.
As a general rule, I look at other Tree info for guidance, not actual connection, as I found quite early on that other people are often so keen to 'get' info that they don't always check it properly, but it's fine for clues. The 1911 census has the most info, as it includes the number of children born, living and who have died, so you have a window to narrow searches.
I simply love the detective work, and I can get lost in the Tree for hours at a time
If you want to tell me (here or via PM) where you're stuck, I'm happy to help if I can.