1) DO NOT forget negatives otherwise you will BURN a lot of money. Most people just disregard negative keyword phrases. That's sometimes what separates a losing campaign from a winning one.
2) Start with exact match and once you get your rates, try adding phrase match. I wouldn't advise you to play with the broad match because you might get lots of irrelevant clicks.
3) ALWAYS track your keywords so you can drop the ones that are not converting. This will also increase your ctr (click through rate) and you'll have a better account history. Use prosper if you want a free solution.
4) Split test your landing pages. Group your keywords and design your landing pages according to your set of keywords. This way, you'll know which landing page is converting better. Then, you should start tweaking to get the best out of your landing page.
5) NEVER change more than one area at a time of your landing page. Otherwise you'll lose track and you won't be able to know what caused the difference.
6) Get your hands on MNF and MS. They will help you when you're doing your market research.
7) You should always understand and analyze the demographics of your niche market. Without that, you won't survive.
8) You should create different campaigns for search and content. NEVER use them both.
9) For content, you can use larger set of keywords.
10) ALWAYS do bid shifting, starting HIGH. DO NOT start low. It is very hard to keep up and ctr is very important for your account history to get cheaper clicks. So, if you start low then you'll get less clicks so your ctr will be low and someone else will get a better spot with a cheaper cost per click, while you are paying MORE for a lower spot.
11) Your conversion rate should ALWAYS be equal or less of the percentage of your commission. For instance, if your pay per click cost is $1.25, your commission should be $125 or more to be profitable. For a conversion rate of 1% for the product you are promoting, for every 100 clicks you'll spend $125 and you'll make it back with one sale. This will keep your campaign close to the breaking point. If your conversion rate is 3% for a 1$ cpc, you can't promote a product that gives you $15 commission per sale. Actually, unless you are a pro in adwords i wouldn't recommend going after campaigns that have $1+ cpc.
Most people do not think about this and then they end up with losing a lot of money on adwords. Find cheap clicks, test, tweak and scale it up. Good luck
