I can't comment towards active trading strategies, because I don't actively trade. But if you're trading stocks based on fundamental analysis, your trading should be based on price compared to estimated intrinsic value. That alone should drive your decisions - not the percentage that the stock has gone up or down.
If you think a stock is worth $100 per share, and you buy it when it's $66 (33% discount), selling because it's gone up in price by $10 would be silly. Yes, you've made a gain. But if your analysis was conservative and accurate, you've still got a ways to go before it gets to 'fair value'.
Alternately, let's say you buy the same stock at $66, and you think it's worth $100. A few days later, the company puts out a press release: its new product causes fires. In orphanages. With crippled kids. The stock drops to $60 per share. Now, you re-run your numbers after reading the info. Maybe even you go the extra mile and talk to your actuary friend and call the company's investor relations department. After factoring in their estimated liability for this awful new product, let's say that the company is worth $50 per share - NOT the $100 you estimated. So now, according to your research, the stock is overpriced by $10. Why would you dollar cost average into this stock just because it went down?
If you are going to invest in individual companies, seriously examine the companies that you want to invest in and attempt to figure out a conservative estimate of what the business is worth. This is your "intrinsic value". When a company trades for a lot less than its intrinsic value, you can consider it as a buying target on your shopping list. When a company is trading for above its intrinsic value, you should consider selling some or all of the position (if you own it). The greater the deviation from a conservatively calculated intrinsic value, the more seriously you should consider taking action (discount to IV = buy. Premium to IV = sell).
Intrinsic value is a bit like calculating the price for a used car - you're going to come up with an "approximate" number that seems pretty fair. You won't nail it to the penny; that's ok. But you'll figure out a price at which you feel the car is "fair", a point at which it's "probably pretty cheap", and a point at which it's "too damned expensive." And that's about how it should be with stocks - you won't nail it to the penny, but you'll come up with a "fair" range for the stock, and when it's far outside that price? That's when the stock starts to be a bit more interesting and you might consider buying or selling some.
Trading strategies like you've discussed - based on percentage movements - has nothing to do with ownership in a business. Remember that you don't just own pieces of paper that represent shares. You own a slice of a company. That company may be fairly priced, over-priced, or under-priced. If you are going to own individual stocks - you should have an opinion on the prices of companies you own and how their stock price relates to your 'fair' price for the company.
I know that many people on the MMM boards swear by indexing, and that's cool with me - I index the majority of my portfolio. But for the portion of your portfolio that you actively manage? Please, treat it like an actual job, because it should be one if you're going to attempt to do it. You do not need to have fifty pages of discounted cash flow spreadsheets for each stock you own. But a few pages of your own research, and your own calculations, showing why you think a stock is worth owning? That would probably help you take the exercise more seriously and keep a closer eye on your individual stock positions.
So my suggestion would be: adopt value investing tenets, if you're going to invest in individual stocks. Your investing should be based on more than just a hunch, or a chart, or percentage movements in a certain direction. You should be able to explain what your companies do, why you own them, and at what prices you would consider buying more or selling. If you want more info, I can send you a list of suggested reading. If this piques your interest at all and you want to just scratch the surface, you can go borrow "The Intelligent Investor" by Ben Graham from your local library.
Good luck!