DCFIFO and external syncronizer

No. The whole point of the DCFIFO is to take care of the synchronization for you. There tend to be four basic synchronizers commonly used:

1) DCFIFO - takes the most logic and has the most latency, but generally the most robust. The big thing is that it works for busses, i.e. if you're sending 8 bit data, it will remain aligned on the output. Throughput is also very high, and it can store data to handle the clock rates.

2) Hand-shaking - Only works when the data rate is slower than the clock rates. In essence the data is presented with a valid signal, the receiving data sees the valid signal and acknowledges it got the data, and the sending domain lowers valid and prepares the next bus of data.

3) De-metastabilizing(probably a better term). This is just double or triple registering the data in the new domain, so that the final register is never metastable. Works nicely for individual signals, but there is no alignment across the bus.

4) Don't care. This really isn't a technique, but often sigals that cross domains are a false path, and so nothing special is done in the RTL, just the data transfers domains directly and the user puts a false_path assignment on it. This usually means the soure is either constan, or the destination really doesn't care(i.e. it might drive some LEDs)

I'm sure there are more. DCFIFO is probably the most common.