@Mark **********
Your first entry is no issue at all.
For the 2nd entry, make sure you have the 3 proofs. If for some reason they want to give you trouble, it will be them asking for one of those proofs.
1) Proof of funds (20,000 baht or equivalent in another major currency IN CASH ONLY)
2) Proof of onward travel (a ticket out of Thailand within 60 days of your arrival)
3 Proof of lodging (at least a week or two of hotel reservation)