I used DMC embroidery thread (full thickness) for this as it was all I get my hands on at the time.  I think using a Perle 5 cotton would be nice and probably easier, as embroidery thread tends to split easily and makes it difficult to work with. 

Ch 4 to begin leaving a long length of thread to complete tassel later.

Note: the turning chain at the end of each row does not count as a stitch.

1^st row:  3 hdc in 3^rd chain from hook.  Ch2, turn.

2^nd row:  Hdc in each stitch. (3hdc)  Ch2 turn.

3^rd row:  2 hdc in 1^st stitch.  1 hdc in next stitch.  2 hdc in last stitch.  (5hdc)  Ch2, turn.

4^th row:  2 hdc in 1^st stitch, 1 hdc in next 3 stitches, 2hdc in last stitch.  (7hdc)  Ch1, turn.

5^th row:  Sl stitch to 3^rd stitch.  Ch1, hdc in same stitch.  Hdc in next 2 stitches.  Ch2, turn. (3hdc)

6^th row:  2 hdc in 1^st stitch, 1hdc in next stitch, 2hdc in last stitch.  Ch2, turn.  (5hdc)

Rows 7 to 9:  Continue in same way, working 2hdc into 1^st and last stitch of each row.  Row 9 should have 11 stitches.  Ch1 only after 9^th row.

10th row:  sl st to 5^th hdc.  Ch1, 2hdc in same st.  1 hdc in next stitch.  2hdc in next.  (5hdc)  Ch2, turn.

Trunk

With brown thread, chain 9 to begin.

1^st row:  Hdc in 3^rd chain from hook and each chain across.  Ch2, turn

2^nd row:  2hdc in 1^st stitch, hdc in next 5 stitches, 2hdc in last stitch.  Ch2, turn.  (9 hdc)

3^rd row:  2hdc in 1^st stitch, hdc in next 7 stitches, 2hdc in last stitch.  Ch2, turn  (11 hdc).

4^th row:  1 hdc in each stitch across.  (11 hdc).  Ch1, turn

With right sides of the bottom of the tree and the trunk together, sl st the two pieces together so that the trunk is in the centre. 

Fasten off and darn in ends.

Tassel

Using the length of thread at the top of the tree, chain 25.  Sl stitch in 8^th chain from hook and each chain back to the 1^st chain.  Fasten off.

Wrap thread 15 times around four fingers and secure at one end with another piece of thread.  Cut in half at unsecured end and loop the tassle through the 8 chain loop.  Trim ends.