Hi,
I have not used the PMDD (poor man's dosing drop) method, but EI will work well for you.
threads are below for more info, but in summary:
We use dry powder ferts for our macros. You just mix with water and dump in the tank water. You can dose daily, 2x, or 3x per week as per your schedule. You can use MORE OR LESS than the thread recommends based on your configuration, plant mass, etc. You need to do 50% weekly water changes which will reset the nutrient level in the tank so you don't get a large accumulation of nutrients.
However, you would need to really overdose to cause issues for the plants and fish in the tank.
Here is a nice thread that speaks to EI and other methods including PMDD:
http://www.barrreport.com/co2-aquatic-plant-fertilization/3205-fertilizer-routines-one.html
and one easy one for EI that is within the above thread:
http://www.barrreport.com/estimative-index/2819-ei-light-those-less-techy-folks.html
and here is a place to get the dry ferts:
Welcome to Planted Aquarium Fertilizer
Please review these threads and come back with any questions.
BTW, are you using or planning on adding c02 either DIY (yeast/sugar method) or via pressurized c02? This makes a huge difference in plant growth.
I hope this helps a bit.