C.,
I'm a mother of a 2-year-old as well, and my husband and I split up last year, so I'm on my own with my son more often than not. He goes to preschool 2 days a week, but I'm a work-at-home mom and I'm home with him for the rest of the time.
I kept my son's pack & play and I use that for time outs. My son is generally pretty good, but here lately he has been having more tantrums - which are more frequent on the days he sees his father. When he goes into tantrum mode, I try to talk to him but I generally can't get him to listen to me. So I ask him if he needs a time out. If he still doesn't calm down, I put him in the pack & play for 2 minutes. After the 2 minutes, I go back and ask him if he's ready to come out and 99% of the time, his attitude is great after the time out. I haven't been successful with a time out chair or corner, but the pack & play really does the job for us. I've been using that method for several months now. I normally give him a warning before placing him in time out. The only time he does not get a warning before time out is when he hits someone (including me) or when he throws a toy while he's in the house (because that could potentially hurt someone).
I've also heard that children tend to be better behaved at preschool or with a babysitter than with their parents, and because of that, they strive and struggle to behave for the hours that their mother is not there. Then they breakdown when their mother is there and the kid just kind of lets loose. They know that their mother loves them unconditionally and will still love them when they are misbehaving and letting off steam and they are more secure with showing the negative behavior to their mother than other caregivers. I think that's what I run into with my son after he has spent time with his father.
I hope that helps,
C.