Hi S.. My daughter is almost 9 months and is going through this right now. She has always been a good sleeper, but she got the flu for a week and got TONS of cuddle time. Now that she is feeling better her sleep is all out of wack.
I choose to do interval sleep training with my girls when they go through sleep changes. It usually takes 3 days of being consistent and things get back on track. When she starts crying I go in after 10 minutes and shoosh and pat (I don't pick her up). When I leave she usually cries harder. I wait 15 minutes then repeat. Then I wait 20 minutes and repeat. I started sleep training when she was 3 month old so my intervals are long now (however she normally settles herself down after 15-20 minutes). When she was younger my intervals were much shorter.
Hannah went through a weird early morning waking period when she was 5 1/2 or 6 months old. She would wake around 5:!5am. The sleep training didn't work for this. I now think that was because she was going through a growth spurt and was hungry. So, for a couple of days, I went in her room at 5am (before she woke up on her own) and I gave her a bottle. I didn't talk to her or jostle her, I just stood by the crib with the bottle in her mouth. She would fall back asleep until I woke her up at the time I wanted her morning to start 6:30 or 7:00am. This worked and re-set her schedule. She was sleeping great until she got sick.
Trust your instincts and try what you think is best for your baby and what you are comfortable doing. It will get better-hang in there!