Tree loving must be approached openly, it is the art of creeping hugging and embrassing the evil inside us.
Step 1. Ignore everything i just said
Step 2. Plant Da sappling
Step 2. Kill some skeletons
Step 3. Burn the skeleton bones
Step 4. Kill some more skeletons
Step 5. Turn the bones into bone meal
Step 6. Throw them in a river
Step 7. Drown in the river
Step 8. Collect the bone meal from the river
Step 9. Right click the bone meal on the tree
Step 10. Go craft a sword