The only thing required to make a raise is to put the chips involved in both the call and the raise forward.
If you do without an announcement, this needs to be done in a single motion, otherwise you may be penalised for string-betting and stuck with a minimum raise (or even a call only, if you had put out less chips than a call plus half the minimum raise altogether).
If you wish to guarantee a raise, say so "I raise" or "raise" is sufficient to assure you can make at least the minimum raise. Again, to prevent string-betting penalties and ensure it is more than minimum raise, put the chips forward in a single action.
If you wish to guarantee your raise amount, state it clearly - "I raise to 200" or "I raise, 200 more" mean different things and you should use the one you mean, or some variation of them. Once you have declares the raise and additional or total amount, it doesn't matter how you put the chips forward, as long as you put forward the correct amount quickly enough (or more than the correct amount and expect change).
An exception to this is to raise the maximum, i.e. all in. You may not need to put any chips forward if the dealer has all-markers, but be helpful and ensure they are within easy reach in the event of side pots or a pot-bet (as is common with PLO).