First, Second, Third, and Finally

Solution 1:

Yes, first, second...finally is fine, as is ...lastly. And firstly, secondly...finally/lastly is also fine. I would probably refrain from using ?last or *final.

Note that the (most) traditional sequence is first, secondly, thirdly...lastly; don't be afraid of "inconsistencies" in idiom! See my earlier answer on ELL and Fowler's Modern English Usage (3rd edition).

The Oxford English Dictionary on firstly:

Used only in enumerating heads, topics, etc. in discourse; and many writers prefer first, even though closely followed by secondly, thirdly, etc.

Burchfield in Fowler's Modern English Usage on first:

Solution 2:

If you feel awkward starting paragraphs with firstly, secondly etc. consider the following expressions as suitable equivalents.

• Initially / To begin with OR to start with (less formal) = First(ly)
• Then / next / after that / afterwards = later
• In addition / additionally = Second(ly)
• Furthermore / moreover OR What's more (less formal) = Third(ly)
• In conclusion / lastly OR in the end (less formal)= Finally

To start with, I grabbed a spoon.
Then I took a bowl and filled it with cereal
Next, I poured some milk into my bowl.
Afterwards I began to eat my cereal and when I'd finished, I drank the milk.
In the end, I tossed the bowl in the dishwasher.

Solution 3:

The following seem to fit into your example:

• Lastly...
• Last...
• And in the end...
• To finish...