These people who keep saying they can force you to give blood in a simple DUI case is crazy! If probable cause exists yes the officer can get a warrant to take your blood by force. They will not get a warrant unless theres a accident or injury involved. Now yes refusal to blow your license will be suspended upon refusal witch is a catch 22 cause your license is suspended soon as your in handcuffs for DUI. Refusal is just an auto 1 year suspension compared to maybe 6months. Yes that seems worse then just blowing. But if you care about a charge on your criminal record witch is priceless to most people. Then the only chance you have to beat DUI is to not blow. The law can't just run around making people give breath and blood test with no probable cause just because there gut tells them your drunk. Why do you think they don't test everybody at the DUI check points because its not legal. when injury is involved its a whole diff ball game there are laws in place to protect me and you from getting screwed by a drunk driver. But going around making people give blood after you pulled them over because your a cop and you feel this person is drunk is preposterous.
Remember that each state has different laws, but your assumptions are largely wrong and your advice is not going to be helpful in a lot of cases. In my state, anyone who operates a motor vehicle on the public streets has implicitly consented to provide blood or breath samples when under suspicion of intoxication. That is the law. Period. Probable cause begins at the traffic stop and no additional effort is needed to establish cause beyond an officer's observations.
In states that require a warrant for a blood test, typically the warrant can be issued as soon as you arrive at the police station based on officer testimony alone. The supreme court is hearing a case now to determine if a blood test even requires a warrant, so your assumptions about the current laws are inaccurate.
Now the issue of refusal is where you're really getting into dangerous territory for me. In Virginia if you refuse a breathalizer test, you're charged with two crimes - a DUI and an unreasonable refusal. So even if you refuse you can still be tried and found guilty of a DUI.
A BAC record is NOT required to obtain a conviction of DUI. In many jurisdictions you do not even have the choice of a jury trial, you are getting a lower court judge and they see DUI cases all day long.
If there's limited evidence to back up suspicion of a DUI, the prosecutor may choose to not pursue the case (I wouldn't count on it), but the refusal is automatically charged based on your arrest and you're out of a license for a year. The refusal doesn't go on your criminal record but the suspension will go on your driving record and could impact future/current employment.
Now here's the tricky part. If you wind up in the same situation and refuse a second time within 10 years of your first refusal, it's a Class 2 misdemeanor with a 3 year suspension of license, fine up to $1,500 and up to 6 months in jail. Third refusal doubles the penalties.
Telling people to just refuse to blow is just not good advice. The only way to beat a DUI is to not drink. There's tons of legal tactics and techniques that might work in a blue moon, but the best advice is to just not drink.