That's how we did the Labrador Retriever this morning. She readily gave me her front feet one at a time and I trimmed all the nails with no fuss. We gave her a short break and my co-worker supported her midsection while I trimmed the rears. No protesting, although she did pull her foot away and whine once. I took that opportunity to tell the owner to "listen to her" because I'd gotten pretty close to the quick.
The second one today we tried to do sitting for front feet but the dog was quite uncomfortable with that. I asked the owner to let her lay down and rub her belly. That worked like a charm! Never once did she pull her foot away or whine, or try to get up. She was in belly-rub-world!
When I first started working at the clinic, it seemed like I only did nails on a dog laying on it's side. That is definitely easier for me to trim, but it isn't always easier for the dog. We always want procedures to be as low stress as possible, but especially for something so simple as nail trim. Let the dog decide where is comfortable, take a reasonable amount of time, and take breaks when needed. Everyone will be happier.
Don't underestimate the power of a belly rub either!