Press x to have a look at your sim's skills and press a for the skill journal to have a look at the milestones for those skills. It's worth mentioning that having more than one sim with the same milestone counts, as my final unlocking milestone was for repairing 10 plumbing objects, something another sim of mine already had. This means it may be worth focusing on some of the easier milestones, for example all of the handiness milestones, and 'specialist writer' for writing (write 5 of the same kind of novel, very easy/quick with sci-fi, fiction or non-fiction). For those of you who are boosting this purely through handiness, if you have a cruel/evil/kleptomaniac/criminal-career sim in your house, you are likely to get firestorms and earthquakes at midnight more often, therefore causing more things to break. If you need further assistance, using the 'epic fail' karma power on a sim before using an appliance is a good way to break it.