A few tips, the real gameplay expert is sake-bento but I've reached almost all endings myself too:
- the thresold amount that will change the ending with the girls is $1000. If you make more than that, you're successful at farming and you'll stay in Fairbrook. Otherwise you'll get the other endings for each girl
- you rarely need to work for the fullday. if you just work in the morning, you should be able to reach $1000 quite safely
- REST! Since you plan the week in advance, is safe to put 1 day to "Relax". If your health is very high, like >90, you can avoid resting that week, but you need to rest as the first day of the next week
- if your health is low, you'll take a FORCED rest, and this will lower all your stats by a bit
- the first week I believe is best to visit all the girls, then you should focus on the activity releated to that girl, example Jogging to get Clara. However, you still need to alternate a bit and not just do that activity and nothing else
If you still can't figure things out, the first line of each of the girls' walkthroughs will give you the main "secret," and the rest will just tell you the exact choices you need to make to raise affection.
-Pay attention to personalities. Not everyone responds to the same actions in the same way.
-Rest is very important! If your health tanks, then your stats will go down and you'll be forced to spend a day resting. Be sure to rest at least once a week. You might be able to get away with skipping rest if you're at full health, but don't tempt fate.
-Spending time with the girl of your choice is important, but don't focus all of your attention on her. Everyone is connected. You can even improve affection meters of one girl by talking with a different girl.
-Buy smart. Some things grow faster, and some things have a better monetary return.
-Plan ahead. You don't want to be caught without anything to plan, so be sure to buy enough seedlings when you visit Susana.
-Stock up. Sometimes seedlings are out of stock, so buy a lot of the good ones when they're available.
-Water last. If you plant new plants after you water, you'll just have to water again.
-Fertilize, but not too often. It's good to shorten growth time, but if you do it too much you'll pay more than you should.
-Jill is extremely motivated and ambitious, and she's frustrated by people who aren't.
-She still feels burnt by your previous relationship, so don't rush things.
-You'll impress Jill a lot if she knows that you're not as lazy as you used to be.
-Marian is older than the other girls, so she does expect you to be more mature.
-Be an encouragement. It really helps.
-You'll impress Marian by being sweet and thoughtful.
-Clara is the most energetic of the bunch. Flirting with her is just fine. In fact, it's probably a good thing.
-Even though she's a strong girl, she needs someone to lean on once in a while.
-You'll impress Clara by staying current with what's going on in the big city.
-Susana's a little different. You'll need to treat her gently.
-Compliments are nice, but actions speak louder than words.
-You'll impress Susana by learning more about the world and appreciating things.
-In order to win a girl, you need to have a high affection meter, a decent amount of her related stat, and a high value of a second stat that the girl values. Each girl has a specific other stat that she values besides her own.
-After you've met Trent and Jacob, spend extra time with Clara until her father's accident. Then visit Susana and you'll have the option of sending flowers to someone. Any girl who gets it will like you a good deal more.
-Strawberries are the best bang for your buck.
-When Jill says that your father wants what's best, drop the issue.
-When Jill talks about her job, suggest that she be a doctor instead.
-After you break up with Jill, call her right away.
-When you call Jill the first night on the farm (assuming that Uncle lets you), make a joke with her.
-During the call, talk about Uncle, then about his cat. Also, talk about your bedroom.
-That night, call Jill and tell her that you met some girls in town, but you're not interested in dating.
-When Jill asks what you're doing with your time, say you're gardening or reading books.
-When Jill is worn out from work, ask her what happened at work.
-When Jill asks how life on the farm is, say it's great.
-When Jill has a new job, encourage her to go for it.
-When Jill says she's on the team for a new project, congratulate her.
-When Marian asks what kind of books you like, say you like poetry.
-At night, read the book of poetry. Seriously.
-When Marian asks if you read the book, say that you did.
-When you're talking about the book, try to pacify her.
-After you say you care about her, thank her for everything she's done.
-After Marian writes a lot of poetry and she is worn out, you can do whatever you please. (If her affection meter is low, don't offer her a back rub.)
-When Marian is shelving books, offer to hold the ladder for her.
-When Marian gets a bad review, tell her to snap out of it.
-When Clara asks if you think this place is the dumps, agree with her.
-When Clara asks if you're jealous, say you're jealous.
-Talk with Jill about the latest summer fashion in LA. Clara will be happy to hear about it.
-After you meet Jacob, visit the flower shop and agree to speak with Clara about her father.
-When Clara asks if you like sports, say that you do.
-When Trent and Jacob volunteer to work on Mr. McFarland's farm, don't say anything.
-When Clara says it's okay to keep running, agree to keep going.
-When Susana chastises you for your eating habits, concede the point.
-Go running with Clara before you visit Susana. She'll be happy that you're working out.
-After Susana gives you soup, ask for the recipe.
-When Susana makes cupcakes, tell her you're willing to wait.
-When Susana asks you your opinion of bees, say that you're afraid of bees.
-When Susana is in a bad mood, leave.
-When Susana is feeling stressed out, offer to make some tea.